According to the user manual page 43-44:
• File types: Your phone can play MP3, M4A, AAC, AAC+, MIDI, and WAV files
https://ss7.vzw.com/is/content/VerizonWireless/Devices/Motorola/droid%20turbo%202/user%20guide/smart...
I might try MP3, as it is the most easily recognized format. If the phone will not play that, you might look into a warranty replacement or defective exchange.