Duplicate user, cannot delete

Nextcloud version (eg, 20.0.5): 22.2.3
Operating system and version (eg, Ubuntu 20.04): Centos 7
Apache or nginx version (eg, Apache 2.4.25): 2.4.6
PHP version (eg, 7.4): 7.4

The issue you are facing:

When one my colleague share me something, in Share to box i am twice, once as name and surname, second as my e-mail address. The e-mail address account isn’t probably me, because if he shared to this, when I logged in I got error File not found. So the account with name a surname is correct one, but I cant find a way to delete the account with e-mail address. Under my account, if I want to share something, if I put cursor in Share to field this e-mail account appears immediately. Maybe it is some guest account when I tried Guests app, but I already uninstalled it and now I can’t find a way how to delete this e-mail account.

Also I found that there are some account with some random number, for example name.surname@example.com and same user name.surname@example.com_1358. I don’t know how that happened and how to change, because account with the numbers is actuali working, not the one without numbers.

Is this the first time you’ve seen this error? (Y/N): y

Thank you very much for any help.