local files disappear from liked songs on droid. Song greyed on playlist but plays from playlist

[lylegold]

Plan

Free/Premium

Country

Device

(iPhone 8, Samsung Galaxy 9, Macbook Pro late 2016)

Operating System

(iOS 10, Android Oreo, Windows 10,etc.)

My Question or Issue

As described in the subject line, I am having major problems with local files. I download them to the pc and it is recognized in my local files in pc desktop app and I place it in a playlist. It works on the desktop. When I connect with my android on my network, it shows up on my playlist and I am able to hit the heart button and it shows up in liked songs.  I have all settings to "downloaded songs"... When I leave the house and disconnect from the network, the local songs disappear from liked songs and become greyed out on my playlist.  However, the song is able to be played from the android device. When I check the pc app when I get back, the song is on the liked songs on the desktop but not on android. If I connect the network, the song on the playlist that was greyed out becomes normal. 

Anyone have any idea? I see people talking about this but not exactly.

Thanks.