Asterisk 13, TCP, Yealink Phones - BLF quits working

Hello all,

I noticed on several systems that if I convert SIP extensions to TCP for Yealink Phones (T2x, T3x, T4x) that BLFs sometimes stop working. Then when converted back to UDP at the device the BLFs continue to work and never go down.

Has anybody else noticed this, is it an Asterisk bug or is it a problem with Yealink phones? I was considering creating a ticket with both, but didn’t want to waste time if people here had seen it first.

Thanks for any insight you can bring!

I have MWI problems with my gigaset on FreePBX 13.0.105 could this be related?

Is your gigaset configured to register via TCP?