I landed on this post after typing into a search engine 'Ubuntu bluetooth keeps switching off immediately after switching on'
The current top answer worked for me and solved my problem:
$ sudo rmmod btusb
$ sudo modprobe btusb
I've been using Ubuntu as my laptop for just over a year and would probably be considered novice compared to most on this forum. I don't understand what that solution is or how it works, but other than bookmarking the post and copy pasting the solution everytime I have this problem, I wanted to ask if there's a more permanent solution or even a gui option that achieves the same result?