Local song won't play on smartphone

[OfficialGxne]

Plan

Premium

Country

Germany

Device

Samsung Galaxy 9 Plus

Operating System

Android 10 on mobile device and Windows 10 on PC

My Question or Issue

Today I wanted to play a song on my smartphone, which I've locally saved on my pc, but Spotify kept skipping that song. Other locally saved songs are playing as usual. On my computer I can play that song without having it skiped. Yesterday I was able to play that song on my mobile device as usual. Since then I haven't changed anything, so I was a little bit surprised.