Yealink phones - 488 Not Acceptable Here

Thank you very much!

Sadly i wasn’t the one who configured the server initialy, but i’ve tried to disable every TLS related setting i could find.

We use a SIP trunk and PJSIP extensions.
I’ve checked the trunk and i did not see anything related to TLS or SRTP only the Profile which is set to “Default SIP Profile”.
I went to the device profiles and the technology settings and disabled anything related to TLS.

I’ve checked the online documentation and a video about TLS and SRTP and i am still getting the “488 not acceptable here” error.

Could you tell me what did i miss?