Сущность в Symfony 4.3 генерирует ошибку 502 Bad Gateway

Разрабатываю локально небольшой проект на symfony. Использую докер. Сайт на symfony 4.3.11 В процессе разработки внезапно на нескольких страницах сайта получил ошибку 502 Bad Gateway nginx/1.15.12

Я выяснил, что эта ошибка появляется только на страницах, где через ParamConverter подгружается сущность Project

public function show(Project $project): Response

Где-то в ней затесалась ошибка, вот только не могу понять где. Ранее эта сущность работала нормально. Никаких ошибок, ни при очистке кеша cache:clear, ни при генерации миграции не выводилось Project:

declare(strict_types=1);
namespace App\Model\Work\Entity\Projects\Project;
use App\Model\Work\Entity\Members\Member\Member;
use App\Model\Work\Entity\Members\Member\Id as MemberId;
use App\Model\Work\Entity\Projects\Project\Department\Department;
use App\Model\Work\Entity\Projects\Project\Department\Id as DepartmentId;
use App\Model\Work\Entity\Projects\Role\Role;
use Doctrine\Common\Collections\ArrayCollection;
use Doctrine\ORM\Mapping as ORM;
/**
 * @ORM\Entity(repositoryClass="App\Model\Work\Entity\Projects\Project\ProjectRepository")
 * @ORM\Table(name="work_projects_projects")
 */
class Project
{
    /**
     * @ORM\Column(type="work_projects_project_id")
     * @ORM\Id
     * @var Id
     */
    private $id;
    /**
     * @var string
     * @ORM\Column(type="string")
     */
    private $name;
    /**
     * Порядок сортировки для отображения на сайте
     * @var int
     * @ORM\Column(type="integer")
     */
    private $sort;
    /**
     * @var Status
     * @ORM\Column(type="work_projects_project_status", length=16)
     */
    private $status;
    /**
     * @var ArrayCollection|Department[]
     * @ORM\OneToMany(
     *     targetEntity="App\Model\Work\Entity\Projects\Project\Department\Department", mappedBy="project",
     *     orphanRemoval=true, cascade={"all"}
     * )
     *
     * @ORM\OrderBy({"name" = "ASC"})
     */
    private $departments;
    /**
     * @var ArrayCollection|Membership[]
     * @ORM\OneToMany(targetEntity="Membership", mappedBy="project", orphanRemoval=true, cascade={"all"})
     */
    private $memberships;
    public function __construct(Id $id, string $name, int $sort)
    {
        $this->id = $id;
        $this->name = $name;
        $this->sort = $sort;
        $this->status = new Status(Status::ACTIVE);
        $this->departments = new ArrayCollection();
        $this->memberships = new ArrayCollection();
    }
    public function edit(string $name, int $sort): void
    {
        $this->name = $name;
        $this->sort = $sort;
    }
    public function reinstate(): void
    {
        if($this->status->isActive()){
            throw new \DomainException("Project already active.");
        }
        $this->status = new Status(Status::ACTIVE);
    }
    public function archive(): void
    {
        if($this->status->isArchived()){
            throw new \DomainException("Project already archived.");
        }
        $this->status = new Status(Status::ARCHIVED);
    }
    public function addDepartment(DepartmentId $id, string $department_name): void
    {
        foreach ($this->departments as $department){
            if($department->isNameEqual($department_name)){
                throw new \DomainException("Department already exists.");
            }
        }
        $this->departments->add( new Department($this, $id, $department_name) );
    }
    public function editDepartment(DepartmentId $id, string $name): void
    {
        foreach ($this->departments as $department) {
            if($department->getId()->isEqual($id)){
                $department->edit($name);
                return;
            }
        }
        throw new \DomainException("Department is not found.");
    }
    public function removeDepartment(DepartmentId $id): void
    {
        foreach ($this->departments as $key => $department){
            if($department->getId()->isEqual($id)){
                foreach ($this->memberships as $membership) {
                    if($membership->isForDepartment($department)){
                        throw new \DomainException("Unable to remove department with members.");
                    }
                }
                $this->departments->remove($key);
                return;
            }
        }
        throw new \DomainException("Department is not found.");
    }
    /**
     * Имеется ли такой учасник в текущем проекте?
     * @param MemberId $id - ID учасника
     * @return bool
     */
    public function hasMember(MemberId $id): bool
    {
        foreach ($this->memberships as $membership) {
            if($membership->isForMember($id)){
                return true;
            }
        }
        return false;
    }
    /**
     * @param Member         $member
     * @param DepartmentId[] $departmentIds
     * @param Role[]         $roles
     * @throws \Exception
     */
    public function addMember(Member $member, array $departmentIds, array $roles): void
    {
        foreach ($this->memberships as $membership) {
            if($membership->isForMember($member->getId())){
                throw new \DomainException("Member already exists.");
            }
        }
        $departments = array_map([$this, 'getDepartment'], $departmentIds);
        $this->memberships->add( new Membership($this, $member, $departments, $roles) );
    }
    public function editMember(MemberId $member, array $departmentIds, array $roles): void
    {
        foreach ($this->memberships as $membership) {
            if($membership->isForMember($member)){
                $membership->changeDepartments( array_map([$this, 'getDepartment'], $departmentIds) );
                $membership->changeRoles($roles);
                return;
            }
        }
        throw new \DomainException("Member is not found.");
    }
    public function removeMember(MemberId $member): void
    {
        foreach ($this->memberships as $membership) {
            if($membership->isForMember($member)){
                $this->memberships->removeElement($membership);
                return;
            }
        }
        throw new \DomainException("Member is not found.");
    }
    public function isActive(): bool
    {
        return $this->status->isActive();
    }
    public function isArchived(): bool
    {
        return $this->status->isArchived();
    }
    public function getId(): Id
    {
        return $this->id;
    }
    public function getName(): string
    {
        return $this->name;
    }
    public function getSort(): int
    {
        return $this->sort;
    }
    public function getStatus(): Status
    {
        return $this->status;
    }
    /**
     * Возвращает объект Department по переданному ID департамента
     * @param DepartmentId $id
     * @return Department
     */
    public function getDepartment(DepartmentId $id): Department
    {
        foreach ($this->departments as $department) {
            if($department->getId()->isEqual($id)){
                return $department;
            }
        }
        throw new \DomainException("Department is not found.");
    }
    /**
     * Для того, чтобы выводить департаменты в шаблоне
     * @return array
     */
    public function getDepartments(): array
    {
        return $this->departments->toArray();
    }
    public function getMemberships(): array
    {
        return $this->memberships->toArray();
    }
}

И почему не выводится, стандартная отладочная панель Symfony?

В логах докер контейнера nginx это:

192.168.99.1 - - [01/Feb/2020:19:03:59 +0000] "GET /work/projects/ee0fc92e-93f6-4f52-833f-91c0a4777aaf HTTP/1.1" 502 560 "http://192.168.99.100:8080/work/projects/ee0fc92e-93f6-4f52-833f-91c0a4777aaf/settings/departments" "Mozilla/5.0 (Windows NT 6.3; Win64; x64) A
ppleWebKit/537.36 (KHTML, like Gecko) Chrome/79.0.3945.130 Safari/537.36" "-"
2020/02/01 19:03:59 [error] 6#6: *327 recv() failed (104: Connection reset by peer) while reading response header from upstream, client: 192.168.99.1, server: , request: "GET /work/projects/ee0fc92e-93f6-4f52-833f-91c0a4777aaf HTTP/1.1", upstream: "fastcgi://172.26
.0.3:9000", host: "192.168.99.100:8080", referrer: "http://192.168.99.100:8080/work/projects/ee0fc92e-93f6-4f52-833f-91c0a4777aaf/settings/departments"

Но я думаю, ошибка именно в сущности, т.к. остальные страницы сайта работают отлично.