Hi all,
I was having problems with my Bluetooth keyboard and mouse.. loosing the connection all the time.
So, after some investigation.. error logs and so on.. I was able to fix it!
Never failed again. Posting here the solution in case someone else is having problems.

My hardware specs:
- Sony Vaio PRO13 laptop
- Dell Premier Wireless Keyboard and Mouse - KM717

Steps to fix it:
1) edit this file: /etc/default/tlp (more info here:
https://linrunner.de/en/tlp/docs/tlp...anagement.html )
2) search for
USB_BLACKLIST_BTUSB
3) uncomment it and set the value to 1 (this means that whatever happens in terms of power management of the laptop, the bluetooth devices won't be turned off/suspended)
like this:
# Bluetooth devices are excluded from USB autosuspend:
# 0=do not exclude, 1=exclude.
USB_BLACKLIST_BTUSB=1

4) reboot the laptop (or should be enough to restart the tlp service:
# tlp start )

That's it! Keyboard and mouse never failed again regardless of the laptop battery level.