Resuming song from where i stopped it on previous run on my next run from internal storage

it could be me being silly, but i cant work it out so here i am.

I have downloaded audiobooks onto my watch hard drive, when i stop a run i pause them, however when i go for my next run i seem unable to resume it from where i left off, i can on spotify, i just hit play and it will carry on even if halfway through a song, but not my 2hr songs. Any advice please?