No Fingerprint (=Touch ID) after some time with a paired Bluetooth keyboard / mouse set. How to get the fingerprint feature back without a restart?

After working with a Bluetooth keyboard and mouse set for some time, my iPad will often drop the fingerprint feature. That does not stop me from working with it since I can enter the password instead. Meaning: that even if I just want to wake up the iPad again, I have to enter the password. I can switch this off in the iTouch settings for the little while I am working with it until I restart my iPad (and mind to switch the iTouch on again, of course). But some things can only be done with the fingerprint. For example, I would like to enter my iCloud website with a password that I do not know by heart. And enter the password menu, I need to put my fingerprint on the home button to get there with no way to just enter the password menu with the Apple ID password. I have already: - Switched off Bluetooth - Looked around in **Settings** > **Touch ID & Code**: - Deactivated the Touch Code and activated it again - Tried to add another fingerprint = Touch ID next to the one that is already there. But for that, I need the fingerprint feature on the home button to work at all. And that does not work, else I would not write this question here :). - Tried to open **Settings** > **Passwords**, but that needs the fingerprint as well. Of course, the feature is back after a restart, but I want to know how to fix this on the run since it happens too often when the Bluetooth set is paired with the iPad. How to get the fingerprint feature of the home button back without restarting the iPad?