With reference to this thread/post
https://getmusicbee.com/forum/index.php?topic=4451.msg185971#msg185971When using multiple entries in the Publisher tag, MB recognises the "; " separator in some areas but not in others.
In the thumbnail browser, the items are split into separate tags, but only the first entry is populated.
In the library explorer the tag is not split and is treated as one string.
Also no Right-click> Paste Artwork available in thumbnail browser when Publisher selected.