Why is my downloaded music on Apple Music not playing when I’m disconnected from WiFi?

All the songs play fine when connected to WiFi, however once WiFi connection is lost I go to the downloaded music section and select a song however the time bar remains on the zero mark. Additionally if the songs are on the recently downloaded list that appears as you open the app in the library it will play without a WiFi connection, however if you search for the same song on the complete list of downloaded music and select it from there it will not play without WiFi. Can anyone provide assistance in resolving this issue? Thank you.