Cannot send to android phones from my iPhone 13 Pro.

I have an iPhone 12 Pro Max. It also will randomly refuse to send messages to android phones. I have all the settings recommended in these posts, set correctly. I talked to my cellular carrier about it and they recommended a factory reset to make it work correctly. Currently, I have to do a forced restart and that usually fixes it. I was considering getting the iPhone 13 Pro just to fix the problem, but, now I see that the 13 has the same problem. Why did this suddenly start happening?

I just picked up the iPhone 13 Pro Max as well. Once I got it, I found I no longer could send messages to any Android users. Took it back and 30 some minutes later, I was told they had to reset the phone so that I could send / receive messages from Android users.

Now I have another issue:

My MacBook Pro, MacBook Air (brand new as of a month ago), and my iPad Air 2 - none of them will send messages to Android users. I have spent the last 3 hrs on my MacBook Pro on YT, reading forums, etc etc., trying to get just this one laptop to allow me to send/receive messages and NOTHING works. Beyond peeved that I paid this money for the 13 and getting this incredible headache.

Hoping that the new iOS system updates in the future fix this issue.

Have you checked with your cellular carrier to be certain your account is set up for MMS? That may cost extra.