Hi Partisano,
welcome to the Apple (user-to-user) Community!
Re: "Hearing aid problems: Since downloading IOS 17.2.1 my hearing aid pairing keeps dropping out.
I can temporarily fix it by switching off and re-pairing but that doesn’t last.
Is there a proper fix or is there a problem with the update?"
Seems others have also experienced problems ... you are not alone, and not all solutions work for everyone
Some seem to have solved the issue themselves, while others have had no success as yet.
Some possible solutions:
✽ Hearing-aids need to be in pairing-mode, and may need to be moved closer to iPhone in order to connect
✽ Check the Settings to make sure your hearing aids are listed correctly, and are available there, for connection.
✽ Turn Bluetooth off, wait a few seconds, and turn bluetooth back on.
✽ Restart iPhone to re-establish the connection. Restart your iPhone - Apple Support
✽ Solution below was posted in another discussion thread:
(Worked for some who tried it, but also did not work for others.)
Bluetooth issues on my iPhone adter iOS 1… - Apple Community
Solution to Bluetooth not connecting after IOS 17 update.
turn off wifi
turn off cellular
turn off bluetooth
turn on Bluetooth only
connect to Bluetooth device
turn on wifi
turn on cellular
✽ Try Force Restarting iPhone: How to: Force restart iPhone - Apple Support
✽ Check with your hearing-specialist or the hearing-aid manufacturer (Eg: contact "support" on their website)
for a possible hearing-aid firmware update, or, if you use an app, an app update.
✽ Else: If needed: You may want to send feedback to those who work behind-the-scenes at Apple.
They will likely not reply, yet your feedback will reach those who can make changes (eg: in a future update).
Web-form for Feedback to Apple: Feedback - iPhone - Apple
All the best :-)