Database freeze: can't add or remove user from groups

Gitlab is not showing user’s project.
Even after adding a specific user to a group/project, this user can’t see anything.
Then I tried adding a new user and adding it to the group/project, and the same issue happened.
I also tried to remove user from group and user has still access to that project (even being private and user not allowed on it).
This is happening after the last upgrade.
I’m not sure if there’s a gitlab limit that is causing this issue.
Any help would be appreciated.
Thanks in advance.