Why does the Music App split albums when you upload

I have several albums in the Music App that on my MacBook that were either loaded from a CD or download off Amazon and for some reason to app splits up the songs into different albums. In the image below off my MacBook the double album downloaded and split it into three, 2 files had one song and all the rest were in the last file. I have dozens of albums that have been randomly split like this and obviously won't play all the songs as one album.

Does anyone know why and how do I merge all the songs back into one original single album, please? It does it on my MacBook and even worse on my iPhone and iPad. When I sync either iPad or iPhone with music library, it corrupts all the albums. I have the latest iOS on both and have even tried removing all the songs, deleting the Music App and starting over with the same result. Any ideas please?

On my iPhone it did this, several songs in different files and one with the rest...??

Please don't judge me by my music... Hehe!

TIA