When I log out of BOINC (V8.0.2), I thought there is an option to stop BOINC processes running in the background.
However on my W10 PC, I noticed that in "Task Manager/Background Processes", there is "BOINC Client" and "Amicable_v_3_03" running. Doing some searches, I found that "Amicable_v_3_03" is linked to Science United, which is linked to BOINC.
So, in answer to my question, Should "BOINC Client" and "Amicable_v_3_03" be running?

Open BOINC Manager, Options, Other options and check the status of Enable Manager exit dialog?
If that's unchecked, check it and try to exit BOINC Manager again. It will now give you a choice to exit and stop the client and the tasks as well, plus the option to remember this decision. If you leave it unchecked, the client and tasks keep running when you exit BOINC Manager.

You've probably once checked to remember the decision with leaving the tasks running.

You've probably once checked to remember the decision with leaving the tasks running.

True for Windows machines. (Just checked on the instance I have running in my VM.

Not so simple at least on my Ubuntu 24.04 installation. The exit dialogue comes up but the only box to tick or untick is the, "Remember this decision and do not show this dialogue." one. It has, "If you also want to stop running the tasks, choose from the following options:" But the option to stop running tasks isn't there. From the file menu there is the option to shut down the running client which I haven't tried yet.

Edit:If I opt to shut down the running client first, the dialogue for stopping tasks then appears when I close the manager.

Thanks for all your replies.

I have gone into BONIC Manager/Options/ Other Options (labelled as Options) and all four options were ticked.

After checking that the four options were checked, I have logged in and out of BONIC a few times and everything now seems to be working correctly, in so much as "BONIC Client" and "Amicable_v_3_03" now no longer appears in "Task Manager/Background Processes", which is how it should be.

(NB. When I had a problem with "Amicable_v_3_03", it was generating 1.400MB in the "Task Manager/Background Processes", after I had logged out of BONIC - ODD. When BONIC was running, it was running through a program called "Amicable Numbers", so "Amicable_v_3_03" was obviously a left over process.)

As I have said, thanks for your help, I will have to keep an eye on "Task Manager/Background Processes", when I log out of BONIC.

To shut down boinc client on ubuntu you will have to run

sudo systemctl stop boinc-client