I had the same problem; the solution proposed above (disconnect iPad from smart keyboard) worked. I did not need to disconnect any other bluetooth devices.
Sorry to hear that. There was a similar issue by another user. They later followed up that disconnecting the Smart Keyboard solved their issue of disappearing UI elements. Until we issue an update asap that fixes iOS 15 (almost there) bugs like the one you're having, we therefore suggest:
- Disconnecting the Smart Keyboard temporarily to see if this works around the bug.
- This issue extends to other peripherals that may be communicating with your iPadOS (or iOS) device. Therefore, we also suggest disconnecting those other peripherals completely but only temporarily. This can be any Bluetooth devices and USB enabled devices like 3rd party USB keyboards, or a mouse interface.
- If the above doesn't work, please let us know if disabling Bluetooth temporarily, via the instructions here, under the section "Turn Off WiFi and Bluetooth", might work around it.
This and other compatibility issues with iOS 15 are top priority. Please let us know if any of the above tips might have been helpful; or if anything else you tried got this dialog to appear properly.
turning off Bluetooth appears to resolves it.
(iPad pro. iOS 15.5