Android system refusing to delete google account
I have two terminals of this model, one of which as started replying that account elimination can not be performed due to administrator permissions.
On my personal terminal this is not happening but after going through all the settings in both phones I can see no differently set security options.
This terminal runs an Android 6.0 system.
I've already went through web searching and, theoretically, after disconnecting all auto update options, I should be able to delete the account but the system keeps replying the administrator does not allow for such operation.
This type of behaviour sounds to me a lot like a root kit or other malicious update that got way into the phone but there are no "iffy" programs installed, on either terminal.
Can someone give me a hint on this?
I know that factory reset is always an option but its one I only want to resort if no other option can be found because it won't truly shed any light on what caused this to begin with.