Bluetooth keyboard disconnects with short timeout during session OR How to Turn off Auto Suspend for Bluetooth

This bug ticket suggests you could try to disable Bluetooth autosuspend by adding kernel option:

rpm-ostree kargs --append="btusb.enable_autosuspend=0"

(Do not forget to reboot after this modification.)
You can read current value like this:

cat /sys/module/btusb/parameters/enable_autosuspend 

On my Aurora install it seems that autosuspend is by default enabled.

If adding kernel option does not help, you can remove it by running

rpm-ostree kargs --delete="btusb.enable_autosuspend=0"