System resources taken by invisible process - system slow down

Maybe im being paranoid but i cant see why my PC is slowing down so much. There seems to be a discrepancy between what TOP is showing and the system monitor app. TOP shows nothing more than 10% from the top two processes but sys monitor showing 40-60%. Any recommend an app for trying to understand whats happening here? I run KDE in Tumbleweed. Tried ICE WM and LXQt but still slow.

Tell us about your system. Run the following in Konsole, and paste input and output here using code tags:

inxi -Faz

How long since the original installation? Is persistent journal enabled? Is snapshotting enabled? How much freespace is there on your / filesystem?