why do downloaded songs stop playing after 15 seconds when offline?

for a couple of weeks now apple music isn’t working fine for me. almost all of my downloaded songs won’t play for more that 15 seconds and that happens only when i am offline. i repeat, the songs are downloaded. i’ve searched it ln youtube to see if someone else faces the same problem but can’t find any relevant content..maybe there’s something that has to do with the new dolby atmos and lossless update but i don’t know..