Maybe TMobile is doing you a favor is showing just how insecure 2FA via SMS really is.

Doesn't Twilio offer TOTP? SMS-based is pretty insecure as far as 2FA goes.

Probably a double irony because twilio is used for sending a lot of spam SMS.

Twilio is often a source of the spam texts and calls, so it would make sense for a cellular service provider to block them.

It isn't just Twilio. When I had T-Mobile, I was able to get 2FA SMS from about 1/3 of the companies that I use it with. Even financial companies like Vanguard and many others, never were let through with T-Mobile. I called T-Mobile and asked them to open it up completely. No improvement.

I switched my same phone with same phone number to another provider and I get all texts that I am hoping to get now and get literally no spam texts.

They switched this off for everyone at some point. Call customer service and they'll turn it back on.

Use the Authy app then

The Authy app is not exactly TOTP - it's a bastardized version that requires you to supply a phone number to use it because that is what they use as a seed. Since twilio is a spam company, I would advise against this.