MESSED UP TRACK ON PHONE

Hello.

Sooo I started making music on Logic Pro X since the end of June, some mixes were solid, most mixes weren't and a few months go by and I'm making music, mixing, mastering, thinking I'm done, I add the song to my phone and sometimes I cant hear the vocals or the vocals are quiet and sorta morphed but it sounds good on any other device, speakers or headphones.

Have you ever dealt with this before?

Can you help me understand why it's doing this?

Am I doing something wrong?

Can you tell me what to do or give me tips so I can stop the track from doing this please?

THANK YOU