Bluetooth connection lost regularly between Galaxy S8+ and Gear S3

[TheFSG]

I have regular issues with my Gear S3 losing its connection with my Galaxy S8+. Often it won't reconnect without doing it manually.

Has anyone any ideas on possible causes or similar issues and resolutions?

[BandOfBrothers]

This happened with my Gear s2 classic. 

I unpaired the two devices and factory reset my watch. 

Then repaired to set up a new connection and it was fine after that. 

[TheFSG]

I'll give that a go but think I tried that a while back. Cheers