I recognize that this is a problem for many. I have read through many comments with suggested fixes. No luck. I just purchased the R10 this week (July 2023).
I use an iPhone 14Pro iOS 16.5.1
Garmin Golf App version 2.13.1.1
Approach R10 s/n 6PN03xxxx
I have uninstalled and re-installed Golf app and R10.
The R10 will calibrate successfully.
Like many others, when using the R10 the light flashes green, turns solid red during backswing through full swing. No data sent to the Garmin Golf App on my iPhone during the Golf Sim Training session. The phone Bluetooth settings show that the R10 is connected.
Any help would be appreciated.