This is an issue I have encountered only a few times. Here's an example:
double-click stopped working (i.e., to open a folder). I tried again & again - but nothing happened. So I right-clicked and selected the Open with Directory Opus option (which was bolded) and got into it that way. About 5 minutes later, all of the sudden, new windows started popping open representing all those earlier double-clicks! This does not happen often, but when it does, it is disconcerting.
Most recently it happene dshortly after I restarted my computer. Maybe my CPU was busy starting up other apps. Perhaps the listener thread for double-clicks needs to have a higher priority?
I am assuming we are talking about double-clicking folders outside of Opus, with Explorer Replacement turned on.
If it only happens during startup, it's most likely Windows was taking a long time to launch other applications and Opus among them.
Antivirus updates might also mean things are slower sometimes as the virus checker is scanning Opus and other programs again. (Opus updates can cause the same.)
It's also some other component on the system is delaying things in some way. Double-clicks to launch things can go through a lot of different steps and plugin DLLs, depending on what's installed on the system.
It looks like the same issue you were having in another thread: It's waiting for Windows to return basic information about a folder below your OneDrive directory, and that's taking a very long time for some reason.
The information request shouldn't be causing the file to be downloaded (if it's offline) so I'm not sure why it is taking so long, unless the OneDrive folder itself is on a slow network drive, or antivirus is getting involved, or something like that.
Right click and double-click do quite different things, in terms of the code.
At the end of the day, there seems to be something wrong with OneDrive on your system (or something that is interacting with it), as an API call to query simple information that should be very quick is blocking for a long time.