CCX 400 Not Registering with Microsoft SBA

Hi,

I've successfully deployed Microsoft's SBA via Audiocodes and it works fine for the Teams clients part.

Now documentation state that Native Android Teams phone should be able to connect to SBA in case of an Internet outage.

I don't see them in the active user list.

Policy is configured fine.

Certificate on SBA is signed by a public CA in the list of approved CA (Sectigo)

I'm getting a TLS error on the wireshark but i'm not able to find where to upload the SBA cert on the Poly phone.

Anyone had to deal with that kind of issue ?

Thanks