MP3 tags read in top-level directory but not displayed in lower level directories

Windows 10. I see v2.3 tags for all 3000 mp3 audio files in my favorite directory (C:\users\howard\music) (and its sub-directories) but when I change directory to one of the sub-directories, no tags are displayed. Mp3tag was working up to an hour ago, and the files and tags are visible in TotalCommander, for example. I did not change any default options except to disable reading of APE but it does not help. I can move up one directory level to see additional music files.

What about an accidentally applied filter?

A single click to select a folder, then a click on the 'Select Folder' button, opens the folder and displays the files. However, a double click to select a folder does not open the folder. It is equivalent to a single click, and it is then still necessary to click the 'Select Folder' button to open the folder. I expected the folder to open with a double click and when nothing appeared to happen I thought there was a problem.

It would nice if the double click behaviour could be changed to the standard behaviour. Otherwise document this non-standard behaviour.

No further action required.

THe dialogue that you see is the Windows standard dialogue to select folders. So any complaint about the behaviour in that dialogue should be addressed to Microsoft.

Also, I doubt that you see any files in that dialogue as it is to select folders.