Music Will not download appropriately from iMac to iPhone. Regardless of weather I tried to download my whole library or manually choose Music.

I believe since iTunes switched to Apple Music there has been I discrepancy in my downloading capabilities for music. I am unable to download the music that I'm choosing from my computer to my iPhone. For example, if I choose download entire Library it does not do so. If I choose to download genres, it tends to choose whatever it would like. I have since try to delete Apple Music from my phone and re-load it but now my ability to download music is even less. I believe it's taken me back at least 10 years in past music downloads. I have about 140 GB of music and it would only load 85 but now it's less than five gigabytes. Any ideas?