Lag and CPU 100% for about 5 seconds whenever selecting a file from a file-dialog
This started happening to me after I updated to 19.04 and it's been a few weeks now. Nothing seems to solve the issue. I removed any extension I had, but still I see this problem.
To reproduce, just go to any website where you can upload a file. Click on "Browse" (this is already slow, it will take like 1 or 2 seconds to open) then choose a file, then click "Open". This will make the dialog unresponsive for about 5 seconds (while gnome-shell goes up to 100% cpu usage).
This happens with any browser but also with evince and I guess anything which uses the file select dialog.