Browsing internal storage on Android phone on Windows 10 PC

I have a very strange problem. I used to use Opus to manage storage on my Android phone. After upgrading to Opus 12, this is no longer possible. I can work with the SD card storage just fine, but the internal storage on the Huawei itself is just a list of empty folders. If I open a Windows 10 File explorer window, I see the files on the internal storage, as well as the contents of the SD card. In Opus the folders are empty. If I give the ‘calculate folder size’ command, they all come back as zero. Right-mouse click back in Windows File Explorer, and the sizes are calculated correctly.
Any ideas?