Phones logout every night

This system has been in for years and uses Aastra 6737 and 6731 phones. In the last couple of weeks about 8 of the 25 phones will logout during the night and show XXNNXX the next morning. You press the login key and enter the extension and password and it is fine the rest of the day. Next morning, logged out again. Why do these 8 phones do this and how do I stop it? I do not have any queues or agents setup. All phones should stay put.

how to fix this.
Default the phones. Use the End Point Manage to reattach the phones to the PBX.
DO NOT USE THE LOGIN feature to add the phone to the PBX.
You can use the Login/out from the phone apps without issues once the phone is attached to PBX.

Thank you, I’ll give that a try. We do not need nor want the login/out feature. Not sure why all of a sudden these started doing this.

I have seen this before on an Aastra device. IIRC the problem was that the provisioning address was not correct in the phone (but the URL for the XML buttons was correct) so every time the phone did the 24 hour re-sync, it was logged out again. I prob have details off, it was a while ago.

Aastra phones are (nearly) unique in that settings that are added manually to the phone do not get overwritten by provisioning settings, a factory reset is necessary to clear manual settings.