I am annoyed as well. Each time I turn on my radar (I dun like to put it on standby mode even tho it supposedly can last 5 months) I will set it to blink pattern. Then when I start my watch cycling activity and once the watch detects the radar, it will revert the mode to solid light.
Sometimes I forget about it and then it ends up I am draining battery faster than I anticipated.
I will be DISABLING my watxh’s (native) Connection to the radar soon and just turn the radar on manually and set the light modes manually.
Now - won’t this means that I will not be able to see traffic info on my watch coming from the radar? Normally the answer is yes, but I have an ace up my sleeve.
The ace is pending the approval process from the Garmin App Store and the beta is most definitely working as I imagine.