So only the mouse loses connection but the keyboard still works at that time, over the same bluetooth dongle ?
Even when you're using the mouse at that time, or only when it's idle ? You could try to disable the idle timeout, although that should apply for both devices ... so not sure why the keyboard still works
https://askubuntu.com/questions/1264725 ... wer-savingApart from that, do you use something like
tlp for energy saving? (I don't know if this is installed by default in cauldron nowadays)
You may need to check if the bluetooth dongle is automatically put in energy saving mode, e.g. like shown here:
https://ubuntu-mate.community/t/bluetoo ... ode/9168/2