What's eating up my battery?

My battery life seems to have deteriorated since a while now. I don't understand what is eating up my battery when the individual app percentage of usage does not add up. Also Kustom widget shows as running in the background when I have no kwgt widget set up.

I initially thought 5g is the problem but even after turning off 5g I see no difference. I cleared cache as well. The performance profile is set to Standard.

Please help.