VOIP cuts out at 15:12 every time?

hi I have a Cisco SPA122 ATA VOIP system using "Freephoneline.ca". Freephoneline.ca no longer supports this system so I can't ask them but every time I make an outbound phone call, my phone cuts off exactly the same time every call 15 minutes and a few seconds.

However, incoming calls are not affected. I have the set up PDF (doesn't look like I can attach it here). Everything seems to be in order. Maybe Im missing something? What would make it cut out like that exactly the same time?
HMSC, November 2022


done
hi thanks. The first link you sent was a thread I started. I think I have gone over the settings mentioned in the other two threads but I will try again.

HMSC, November 2022
Looks a common problem. See these:

https://community.cisco.com/t5/ip-telephony-and-phones/phone-cuts-out-15-minutes/td-p/4623512

https://btbusiness.custhelp.com/app/answers/detail/a_id/41858/~/im-having-problems-with-sip-and-calls-are-cutting-off-after-15-minutes

https://community.cisco.com/t5/atas-gateways-and-accessories/spa-122-hangs-up-after-600-seconds/td-p/2203108

Ekrifj, November 2022