Help. I cannot successfuly transfer downloaded music to my iphone

Since I lost all the cd albums I downloaded to my itunes library I have had to start manually downloading each album to my windows laptop into audio books on itunes then transferring them to Apple Music library. They carry across okay and I have to add artwork.

The problem is when I come to open Apple Devices app then connect my iphone 13 and try to sync. Only 2 of the 6 albums I've moved into Apple Music appear on my iphone.

Please could someone tell me where I am going wrong and reply with step by step advice so I can overcome this as I've got another 60 cd albums to add.