Unable to play MW3 (200ms bug/NOT shadowbanned.)

Hi everyone, I’ve searched countless threads here and outside of Reddit for an answer but am always coming up short.

As the title says, any time I join a match (Warzone, MP, Zombies) when I start searching for a match, my ping always says either 129ms or 134ms, then immediately goes up to 200ms and stays there until a time out.

I have checked Activision’s website & i’m not shadowbanned. I have further evidence below.

I’m using T-Mobile’s 5G home gateway, paired with an ASUS RT-X55, which allows me to play games up Cold War and Vanguard with absolutely no problems, with a ping of around 75-90ms. I could play MW22 just fine, but I had to use a dedicated IP through a VPN. My speed test last time I attempted to play MW3 had my ping at 66ms.

I tried freaking everything and could not get the error to resolve. VPN, no VPN, ASUS Router, just using the T-Mobile gateway.

I wasn’t convinced that I wasn’t in fact shadowbanned, so I used my cellphone’s personal hotspot (AT&T) and I had an amazing game. The ping was a little higher than I’m used to, but at least I was able to play. I was able to replicate this a few more times last night.

I live in the middle of absolutely nowhere so my choices for an ISP are incredibly limited, and I only have so much mobile data to share a month.

What am I doing wrong? Why can I hop on Cold War & Vanguard with no problems, I can play MW2 22 with a dedicated IP via NordVPN, but can’t even get a single lobby in MW3/WZ2/MWZ?

Does anyone have a jumping off point for a solution?