iMessage Mark as Unread missing in iOS 16

The new features with Messages in the new release seem to be working--with the exception of the missing "mark as unread" option for individual messages. Any ideas?

When I long hold a message down, I can: Reply, Copy, Pin, More (...). More (...) leads to the choice to select and delete, or to forward.

The other strange anomaly is I can not swipe right on an individual message. If I swipe left, I get a timestamp (time message was received?).

Note: I can swipe right on a chat and mark it unread. All other new iMessage functions that I have played with seem to be working without a hitch.

iPhone 13 Pro running iOS 16