itunes 12.8.3 for mac will not switch to server on local network

Trying to change iTunes to a library on a server drive attached to an AirPort Extreme (tall model, local network). It is identical to my current library on one of my computers (just copied over). The server and it's iTunes folder are visible to all computers on my local network and disk password setup is working properly with full Finder access to the server disk. I open iTunes Preferences, Advanced tab, and select the server library. My local library has pointed to my iTunes Music Folder as the organize files folder and works fine. I set it the same way when changing to the server library. (My iTunes was upgraded from a pre "iTunes Media/ITunes Music" version and never adopted the new setup. I only use iTunes for music so never a problem.) The path pane in the Advanced tab shows the server as the current library after selection, not the local library. But when I do "Show In Finder" on a file after the switch, it shows the file in the library in the library. When I add music it shows up locally only. What am I missing here? Thanks for reading!