There is an option to synchronize your play queue for Premium users, I think this also works on mobile devices then. You can find it in the audio quality settings, and it will remember what you have played before changing to another device or restarting it and start with the last song played then.

It's not related.

Evety time I play the Flow playlist another playlist takes over.

I restarted my iPhone and no change

hey there @Tal.Stanek, I don’t understand the problem. 

A playlist plays instead of Flow? 

Can you send us some screenshots please?