SMS/MMS not sending for over a month, Google Pixel 7a from iphone 12

Ever since i switched from my iphone to my new Google Pixel 7a, i’ve repeatedly gotten the following message whenever i try to text my mother, coworkers, wife, and several others including my stepdaughter.

“Free Msg: Unable to send message - Message Blocking is active.”

I have none of them blocked and i confirmed it with t-mobile support, who told me it cannot be anything to do on their end and i have no message blocking in affect on either of my tmobile lines.

I’ve tried taking out my sim and putting it back in.

I’ve tried using downloading and using different text message apps and setting as default.

I’ve tried sending multiple messages once a day for over a month, just to check if it works yet.

I’ve MOST IMPORTANTLY, put my sim back into my old iphone 12 and deactivated “iMessage” after reading on a forum site that usually, that would be the reason this occurs.

Not a single thing i’ve listed or otherwise tried to do to rectify this issue has resulted in any sort of victory.

Most irritatingly, i cannot login to my twitch account and several other website accounts that require 2FA via texting me a security code. I never recieve them and they aren't in my spam & blocked area either. This has prevented me from logging into one of my credit card accounts online!!!!

I still cannot text anyone unless its through the “RCS” messaging that i understand uses my data connection.

I’m on the GoPlus5g Plan, have two phone lines, and this is happening on both lines.

Important to note: anytime i receive or send a call, it goes through lickity-split. No issue with calls whatsoever. This only pertains to texts.

Any tips or solutions would be highly appreciated since tmobile support couldn't help me and i've been losing my mind over it. Thank you for reading this far.