Weird digital noise on remote extension

So I’ve had a remote extension that I’ve been having a lot of issues with. For starters, it’s a cell phone using an app (Bria). I’ve done all of the usual stuff to get the extension to work. I have other extensions that work remotely (I put these up as tests and they work fine through NAT) So I’m not sure if the cell carrier has anything to do with this or not.

The long and short of it is 2 things: The phone constantly keeps dropping it’s registration. I’ve modified the times per an article I found here and I still can’t keep it registered. It misses calls more than it rings. This seems to be a newer issue. Before it would not ring, but would display a voicemail, if one was left. Now it doesn’t do either.

The bigger issue is this weird digital noise, not like a dial up modem but digital hash. (if that makes any sense at all)
The call goes through, but on the softphones end it’s just digital hash.

I’m starting to think I might just have to suck it up and forward to the cell, which I didn’t want to do, to keep some added features of the softphone (hold, transfer, ect) as well as not doubeling my metered extension usage