So, just as an experiment, I'd try uninstalling Discord, then restarting the system, then go back into task manager again and make sure no Discord related processes are still running and if they are, stop or cancel them, and then see if the behavior changes at that point. If not, after making sure that all Discord related processes are either gone or disabled/stopped via task manager or services, then move on to Opera GX browser and do the same thing. Both those programs look like they have way more running processes than they ought to and I know that we've seen a few users with some problems similar to this with Discord before in the past.
That's not to say you shouldn't remove other unused programs and driver packages, as you've discussed already, because often they can be the cause AS can outdated drivers, but I'd still try with removing Discord and Opera GX just to see.
Also, I don't know what that power supply is, because I've never heard of the brand before AND I cannot even find any references to a "Leigo" power supply of ANY kind, but I seriously consider replacing it because the chances are VERY, VERY good that this is a ticking timebomb dumpster fire type of power supply and might even have something to do with the system not wanting to idle if it doesn't support specific power states.