The problem started a few days ago and now it gets high to sometimes 12% and some time to 45% CPU usage. It doesn't start immediately but after a little while if you terminate explorer.exe and start it again.
Here is the WPR recording of the event. I get similar output in process explorer too. I don't know to make sense of it. There is nothing that seems wrong in Windows Indexing either.
I sometimes see explorer.exe is trying to read everything in c:\Users\Username (it's worth 125 GB) which is strange but high CPU usage still happens even without disk usage so I think they are separate issues.