Good afternoon @Feralcat!
I am sorry to hear that you're experiencing such issues with the new update. I'm always concerned about updates and tend to delay installing them until I've checked to see what potential issues might come with the update.
From what I understand, you would need to root your device in order to roll back an OS update on your Android device, which we can't offer support with here. There is no officially supported way of rolling back an update unless the manufacturer issues a rollback themselves.
Rooting is not without risks so I can't recommend it. If you're having Bluetooth related issues, I would recommend checking to see if the Bluetooth enabled devices have firmware updates available. I know this doesn't apply to all Bluetooth enabled devices but it's worth a shot!