Weird Local Song Bug

[Pogogo]

Plan

Premium

Country

CA

Device

Samsung Galaxy S8

Operating System

(Android 9 Pie)(One UI)

My Question or Issue

I have local songs that I synced from my computer to my phone. But for some reason sometimes those local songs turn grey. This happens at random and for no apparent reason. They can be played perfectly fine but are skipped when playing the whole playlist. The only fix I've found is to redownload them from my PC.