Latest firmware for the Polar H10 is version 3.3.1 as of this post.
If you're having connectivity issues with your phone, use the Polar Beat app to check if your Polar H10 has the latest firmware. If the firmware is older the 3.3.1, the Polar Beat app should provide you with an option to update the firmware.
For me, I was on an older firmware, and the H10 kept dropping the connection with my OnePlus phone. I tried using Polar Flow, but the update never successfully completed, and the percentage status bar went up beyond 100% to 160% before failing.
Use the Polar Beat app and update the firmware. If you're still having issues, use another device like a tablet and download the Polar Beat app to update.
Once you see firmware 3.3.1 on your Polar Beat app, then you've successfully updated the firmware to the latest, and the connection issues will be resolved.
