Freeswitch sending NOTIFY packets with wrong presence

Hello,

we currently have a problem with the BLF keys which we use to monitor our internal extensions.

After some time, some of them remain permanently red (indicating “On the Phone”).

At first we thought it’s a Problem with the endpoints but after looking at the Notify packets send by Freeswitch, it showed that Freeswitch is sending a wrong presence for the affected extensions.

We are not exactly sure how Freeswitch determines the presence of an extension but the extensions don’t have any open channels/calls and are registered.

After restarting Freeswitch the presence is working fine for some time but the problem always returns.

Would be nice if someone had some pointers what else we could check.

Is there any way to check the presence of an extension other than subscribing via SIP?

We are running Version 1.10.12 currently.