There is no text box in iMessages to reply, iPhone 11

I have been texting in iMessages a group of 3 no problem. One time the text box under the most recent message didn't appear so I couldn't reply. It had always worked. I rebooted and all was well and they could text me and I could text them, then it happened again. So I rebooted again. After a few times of this I went to the bubbles of the three people at the top of the messages and clicked on where it said 3 People. But it was shaded in gray and I couldn't tap on the side arrow at the right of their individual names. Odd.

I could easily have deleted the message thread and start over but I have wanted to preserve that thread. I have done most everything else suggested. My workaround was I created another group of those three and added my name and all works well and their names aren't shaded over when I go to Info.

Any thoughts? I have the latest iOS 15.5 update.

Thank you!