I've been trying to search for this particular issue, but what I've been finding doesn't seem to fit exactly what I'm experiencing, hence my post here.
I can send and receive normal photos (ones that were taken with the camera) with no issue, however, screenshots do not appear when I receive them (or if I send one, the recipient also does not see them). They appear as a blank message "bubble" and when I click on it, the screenshot appears. Attached is a screenshot of what it looks like in iMessage. I'm curious if this is a bug, or do I simply have some settings incorrect? I'm on the iOS 25.1 beta 3, but this has been happening since iOS 25 launched, and I have a 17 Pro Max.