No, there's no compression/decompression but it takes time for PD to populate the clips each time. You might want to try uninstalling PD and then reinstalling it to see if that helps.
I saw your PM about other issues with your system, and you may want to try the Reset this PC proocedure while leaving your installed programs intact.
If you're up for doing a clean install, that's the best way to be sure that everything is in top condition.
It generally takes me several hours spaced out over about a half day to get a clean build up and running. I recommend that you make a system backup now so you can return to this exact setup if anything goes wrong. EaseUS Todo Home and Macrium Reflect have free versions that will do that.
You should uninstall PD first to clear CL's record of it being installed to free up the license for your clean install, and make sure you have all the installers handy for all of your other important apps.