In the middle of an install right now for UE5.5 and second waiting and leaving it alone, probably.
You will be able to tell whether it’s doing something or not by opening Resource Monitor on Windows and filtering for EpicGamesLauncher in the disk activity tab.
I wanted process-specific graphs that show me resource utilization so i installed System Informer. Seeing that it WAS doing something despite the launcher’s graphs saying otherwise, i just left it alone and had the two windows side by side. eventually it changed from “installing” to “verifying” which is also taking a while, but as long as it’s moving along 
do not pause or restart it unless there doesn’t seem to be any activity or the program stops responding.