One thing I notice on the companion app is that the EVENT COMPLETED flag comes up at the very start of your ride instead of at the end which is when it should come up. When you view your activity on the app you can see how it unfolds on the map and the flag comes up first, then the bike, then the level up and then the new pr.
I don’t know why it’s doing this but the first thing I would check is that your computer time is set correctly. Perhaps daylight saving has set you one hour faster or later than everyone else?
Also, I think you would have a better chance of having this issue fixed if you contacted Zwift support directly rather than posting in the forum. It seems like Zwift doesn’t really solve issues here. And tell them about the event completed flag appearing at the start of the ride, it may help them figure out what is going wrong.