I am using Mp3tag to categorize my own original music, for which it mostly works very well. However, if I change the album tag of a tune (I use the name of the folder in which the tune is stored) Windows Media Player sometimes still shows the tune with the old tag, although File Explorer correctly shows the tune in the correct folder and with the correct album name under the "album" column. If I highlight the tune in WMP and click the "open file location" option, it correctly shows the tune in the appropriate folder and with the correct album name. I thought I had found a work around by changing the tag, saving it and then changing it back to the correct name but this does not now appear to work and WMP persists in failing to recognize the change. This is made more problematic because it does not appear to be consistent and evenutally (in some unknown way) WMP seems to get things right. However it is extremely annoying to play an album of tunes only to find that some which have been moved to other folders (and had the "album" tag altered as appropriate) are still thought by WMP to be in the old album.
Also, if I highlight the tune in File Explorer and click "properties" and select the "details" tab, it correctly lists the album name. If I do the same in WPM and select the "content" tag (the WMP properties option is differently configured) it lists the wrong album name.