More details would help, e.g., screenshots from the iPhone with the complete list and how that looks on the Mac. Anything about which albums are missing, any pattern, e.g, are these local or streaming? Or basically any detail because nobody will be able to answer “albums are not displayed, why?”
Thank you for pointing that out. I am attaching two photos one of the my albums menu on my computer and the other a screenshot from my iPhone. Not a huge discrepancy.
On the Mac, it knows that you have 908 albums, but you have “Jazz” selected as the only genre to display, which is probably what limits it to 150 out of the 908 albums. On the phone it shows all 865 albums.
The 865 vs 908 difference might be caused by having different choices on the Mac and the phone in Settings > General > Browsing Preferences > Show Hidden Tracks and Albums. This would group different versions of an album under its VERSIONS tab if the setting is set to No on one of the devices, which seems a possible explanation for the size of this difference.
I should add that album is not recognized by roon have not shown up on the iMac. Other than that, all the details are in place and I have no problem playing from the Mac or the phone