Incoming Calls Drop or No Audio

[All4Fun]

Hi, I tried to search through this forum but the suggestions don't appear to work for me or my search criteria is not very good.

I just switched over my voip services to voip.ms and VoXalot and I use SIP URI forwarding from voip.ms to VoXalot for my DID.

Problem: When registerd with VoXalot, I can make outgoing calls successfully but when receiving incoming calls, there's no audio between the 2 parties when the call connects or it just drops completely.

I have followed the Wiki configuration for the PAP2 but I'm still having problems.

If I turn off SIP URI forwarding and register with voip.ms directly, everything works fine. (However, I don't get to use some of the preferred dial plans that I have setup with VoXalot).

May I get some help please?