Can not delete an imported LDAP account


First of all, I want to thank the NextCloud community for your very active involvement.
After installing NextCloud v12.0.4 in a training center, I linked it to an Active Directory service. I can see the accounts of users who are members of a specific group.
Problem, I can not delete the imported accounts.
The account gives the impression, a few seconds, of having been deleted then reappears accompanied by an error message: Unable to delete the user.

Should the accounts on the AD side be disabled before attempting to delete them from the NC side?

What investtivations should I lead?