Doctrine ManyToOne relationship - auto-remove on "set" - php

Question

I'm working with relationships in Doctrine (using Symfony 5).
What I have is these 2 relations:
User
Availability
User has an ID and has Many Availabilities.
So Entity User has
/**
* #ORM\OneToMany(targetEntity="UserAvailability", mappedBy="user")
*/
private $availability;
and the reverse on Entity Availability.
Availability is a relation with:
id, user_id, day_name, start_time and end_time, that simple.
What I already achieved with ManyToMany and I want to achieve in this case too is:
I need to receive the entire set of availabilities for a User from the client and use it to update the availabilities of my User, so I defined a setAvailability method which receives a Collection of Availability entities and simply does
$this->availabilities = $availabilities.
This works when I add new availabilities but the ones that are on the DB and not in the collection are not dropped when I persist the entity.
The same method works flawlessly with ManyToMany Relationship.
What am I missing?
*** UPDATE **
public function setAvailability($availability): self
{
$this->availability = $availability;
return $this;
}
this same code works when removing relations in ManyToMany relationship but not in ManyToOne, the attribute "availability" is correctly set, but when using persist/flush the availability which was removed is not removed on the DB.
Thanks

Answer 1

Try to set the attributes as in the example from the doctrine documentation below :
<?php
use Doctrine\Common\Collections\ArrayCollection;
/** #Entity */
class User
{
// ...
/**
* One user has many availabilities. This is the inverse side.
* #OneToMany(targetEntity="Availability", mappedBy="user")
*/
private $availabilities;
// ...
public function __construct() {
$this->availabilities = new ArrayCollection();
}
}
/** #Entity */
class Availability
{
// ...
/**
* Many availabilities have one user. This is the owning side.
* #ManyToOne(targetEntity="User", inversedBy="availabilities")
* #JoinColumn(name="user_id", referencedColumnName="id")
*/
private $user;
// ...
}
the attribute mappedBy and inversedBy are necessary for relations