Inconsistent Views of Group Chat in Messages

In a group chat using Messages we noticed this morning that something odd is happening with the chat history. The group was very active yesterday, looking at the chat this morning we noticed: 1. On four devices, with two different owners (an iPhone Xs running iOS 16.5.1, an iPhone 13 mini running iOS 17.1, an M1 MacBook Air running macOS Sonoma 14.0, and an Apple watch) the chat history was in sync, but there were significant gaps in the chat. These devices are all in Washington state in the US. 2. At the same time, on an Intel mid-2014 MacBook Pro running macOS Big Sur 11.7.10 the whole chat appeared to be there -- when I first woke it up. This device is also in Washington state in the US. But... After typing this, I checked again and the chat appears to have sync'd with the other devices and there are large gaps on this device as well. [Edit -- about 10 minutes later the view on this device seems "right" again, though honestly I'm not positive that the right-wrong-right thing happen since I didn't make a screen capture.] 3. There is at least one other device on the chat, a MacBook, with a **third** view of the chat -- this device is in the UK. Also, during the chat, I think I noticed the iPhone mini changing its view (dropping a bunch of the messages from the chat). This happened after I switched from chatting on the phone to chatting on the MacBook Pro. The chat started with two participants on their phones (I'm not sure about the third, but would guess on a relatively recent MacBook with an up to date version of macOS), then those two switched to MacBooks, and then later back to phones. Any idea what could be going on?