Interference from 3rd party programs most often comes from those that are run at Start up - simplest way to see them is to look in Task Manager Startup tab.
First thing is to disable (button bottom right) the ones you know you don't use, e.g.…
If the fuzziness goes away, problem solved, otherwise disable the rest, if the fuzziness persists the problem is deeper, if it goes away then its one of programs you just disabled… a process of elimination should find it.
BR