This can be solved without * completely resetting the home setup, but it could almost as well.
TL; DR: iOS14 broke the integration of HomeKit and Siri in the Hue app for me, everything got stuck on updating, even though the Hue app was 100% functional, and my non-hue devices worked fine.
1. Hue> Settings> HomeKit & Siri> Advanced> Reset …
2. if you do not do 1 and try to add the bridge, it will be thought that the bridge is already associated, but it will not solve the problem.
3. After resetting, you can re-pair the bridge.
4. If you check your house, your lights should respond now, but they are all in the default room.
5. In Hue> Settings> HomeKit & Siri, run the update to fix the mismatch.
6. Problem: Your rooms are still broken because Hue will not add rooms that already exist.
7. Solution: Hue> Settings> HomeKit & Siri> Cameras
8. From here, tap a room and you will receive a “!” Orange Indicator. A menu appears asking you to rename or overwrite the camera in Home – choose Overwrite.
9. All the lights are back in the right rooms and answer correctly. Your pulse and blood pressure will return to normal.
10. Now you just have to recreate all your areas, groups and scenes!
As a long-time HomeKit user, I just expect iOS updates to break my shit every year right now, but this has been a little tougher than other events. As I said, reading the above, you can just choose to reset everything. Good luck!