2020 FLTRXS, HD 131 Kit, V&H 450, Heavy Breather, Yaffe 12" Bars
That makes sense. That the sock is for when air is not zooming thru. Switch modules are the bars might be interesting to pursue as well. I do have 12" mini apes so they were definitely getting wet.The rain sock is for when the scooter is sitting. It keeps the throttle body from filling with water after the filter is saturated.
Running down the road, the engine just ingests any water that lands on the filter, or sock. And unless you are fording lakes and rivers, its not enough water to greatly effect the way it runs.
For the OP, I would suspect a wet connector. Something out in the weather. The plug on the throttle body is often the issue, but these M8's also have issues with the switch modules on the bars. A look at what the ecm saw might point you to it.