I’ve been having endless problems with getting voice control to find artists on my usb drive after I added more files. I saw a post on another forum that suggested the greying out happened if you added or amended files. There is also some discussion about a maximum number of files for it still to work and some files being greyed out due to protection rights. The post suggested clearing the card/usb drive and loading again. A previous drive I had that worked was 88GB so the number of tracks you are talking shouldn’t be an issue.... good luck
