Emptied those folders, and it still shows 92% full. The new Lightroom has been an unmitigated disaster for me. Not only does it have very limited capabilities but all it would show was five pictures even though as I just discovered with the link you had provided that I had thousands of pictures in there.
It took over 24 hours for it to start reporting the correct usage. I don't know if you can pass on to the lightroom CC people what a disaster the new product is. I will keep using Lightroom Classic and a USB hard drive.
Glad to hear it's showing the correct amount now and you were able to identify the cause. Sorry to hear Lightroom CC wasn't to your liking. I know it's fairly new, hopefully it will get more features and better integration over time.