VoLTE SIP BYE message with cause RTP/RTCP timeout

Hi all.
Someone maybe knows, in VoLTE: SIP BYE msg with the cause RTP/RTCP timeout is alway sent from UE or can be sent from the Network?
I don’t have B side to check and always this call release I see on DL side so to be sure that the problem is on UE on the B side or to investigate further on the Network side.

Check your timer.

This timer is 10-15 seconds.
RTP timeout timer.

Is this timer in UE?

There is timer set at Core, If there are no RTP been sent with specific timer.
How long do you get the RTP.

That is the tricky. I can see normal RTP packet flow until I get BYE msg with the cause RTP timeout
RF good and no HO.
But I don’t have the B side to check.
So this buy msg could be from Network then?