any way to force Polar Beat to sync with Google Fit?

There is, but you need to jump through hoops and is only temporary unless you pay.

The reality is that, rarely, beat or Flow won't sync your workout to Fit. Maybe once every 30 workouts? It's rare. You can't fix it with relinking the services, modifying things like "Mood" or the description, or force sync with swipe down in the apps. Will do nothing.

Probably the only thing you can do (unless you're great a coding) is run an app to force sync. I use Health Sync (I would not have bought if it was just for Polar)

https://play.google.com/store/apps/details?id=nl.appyhapps.healthsync&hl=en&gl=US

I could sync the Polar Beat failed workouts with it by just doing an entire day in the past. Can't guarantee it will work for you. There's a 7 day trial I think.

/r/Polarfitness Thread