iPhone music library not showing all songs on device

After the i0S10 upgrade my iPhone 6plus and my old iPhone 5 do not show all the songs that are visible when connected to itunes.

How do I fix this?

When I connect the iphone 6 plus to the computer it begins to update and theres a new number of songs listed from last I recall. Earlier today, Audio showed 3265 or so songs.

At present... the iPhone 6 plus Summary shows 1,395 songs of "Audio" but when I go to the Music tab (On the Device) it reads 3,258 items

Phoneview only shows 370 tracks on my phone. But I can select 3265 items in the Music tab (on the device) in itunes.

I am set to manually manage music. So no I am not concerned with Apple Music. I cannot seem to find a proper community to post this to.

Help