Have you tried setting the library to 'deep search' ?

Also, Windows can be weird when you copy stuff: I've often found folder 'attributes' set to eg 'write protected'. Worse, may take several attempts to 'un-protect'...

In one case, I had to create a new folder, copy stuff from the intransigent whatsit. Finally, with all contents removed, I could clear the protected flag, delete that folder, re-name its replacement...