I have the same problem. Starting in the second half of November, my four Hue outdoor motion sensors no longer seem to be sending motion events to SmartThings. They are connected to SmartThings via the Philips Hue Linked Service. When I access the Hue Bridge via the Hue app, I see that they are detecting motion. So somehow that motion is not being relayed to SmartThings.
One clue is that when I look at the drivers installed on my SmartThings hub, the Philips Hue driver has version 2023-11-14T19:09:47.293595694. This suggests to me that a new driver was installed just prior to this breaking. So probably the new driver is to blame. Any ideas on how to get this fixed?
P.S. The day after posting this, I linked my Hue service to Google Home using the “Philips Hue” integration in the Google Home app. That works perfectly - motion events are received and can actuate my Meross switches. So this puts further weight on the hypothesis that the problem is on the SmartThings end.