PSTN Call dropping after 10 Seconds on Call Pickup Group

Hi There,

we are using call pickup groups with MS calling plan in teams. After a call is routed to the pickup group it only rings for about 10 seconds - then the call is dropped or routed to the mailbox (depends if cloud voicemail is enabled or not).

In my understanding the call should ring forever at the pickup group.

Whats wrong here?