so I currently have 2 devices connected to the notebook: an MX Keys and a Magic Trackpad.
Sometimes when I try to connect my MX Master 3 to the notebook the bluetooth process crashes.
This is what the bluetooth service gives me when I try to connect the mouse:
you just need to install svn (subversion, you will find it in the aur) and copypaste in the terminal the commands shown in the comment thread I just forwarded. Remember to add the key.