When you say you were given a login prompt, where were you seeing that? For example, if it was on the phone, were you provided with a Login key on the idle screen? If so, the phone sounds like it is pulling a config from the server, it just happens to be one for Hot Desking. This usually happens if a MAC address is not entered in the extension’s mapping in Endpoint Manager.
If that’s the case, you can add your mac to the extension’s mapping and try to reconfigure. As for the failed logins, if the phone was prompting for a hot desking login, the password should be your user’s voicemail password. The global passwords found in Endpoint Manager’s Global Settings should also work.
If the prompt is not related to hotdesking, more details about when the prompt is showing up, or anything else on screen would help to understand what you’re seeing.