Yes, I see the same effect, no period at the end. Question marks and exclamation points do show up, though. I also see it in messages going back into 2019. Odd indeed.
On a Mac since 1984. Currently: 24" M1 iMac, M2 Pro Mac mini with 27" BenQ monitor, M2 Macbook Air, MacOS 14.x; iPhones, iPods (yes, still) and iPads.
