Remember Playback Position Not Working

For some time now, I've had to make a note in Notes of what time I left off on a song because having Remember Playback Position turned on makes no difference. Either when I go back to my iPhone the song has started over of its own accord, or if I've switched to another song, when I go back to the first song, it has started over as though Remember Playback Position was not turned on.

I have tried restoring my iPhone per a previous thread. I have even reloaded the iPhone firmware to start over completely and no change. Another previous thread stated that using Siri to play music would break the ability to Remember, but having reloaded the firmware completely and not using Siri afterwards...that didn't work. I have also tried converting from MP3 to AAC in case that has something to do with it...but it didn't.

I do not have this problem on my Mac...if I'm just playing the song on my Mac it will remember. It's something about the iPhone that refuses to "mark" the position however it's supposed to.

Does anyone have a suggestion for fixing this? Many thanks in advance.