You're looking at two different repositories when you use the two different apps - the phone WiiM Home app knows nothing about tracks the desktop app is pointing to. Each app displays its own local music files when you select My Music/My Library, so I guess what you're seeing on your phone is what you have stored there, perhaps under Apple Music.I created a folder on my external hard drive connected to my Mac. Dragged that folder into the home desktop app. When the cd rips it creates the appropriate folders. Artist/ album / files. On the home desktop app everything appears correctly. However on the phone app nothing looks right. When I click albums. Nothing shows up. When I click all music everything shows up.
If you want to access the files on your Mac/external drive from your phone , then install something like Minimserver on your Mac and point it to your external drive music repository, and then you'll be able to use that under Home Music Share on the phone.