They took my new bike
The dealer went over my bike on Friday for the stalling issue and there were no fault codes and no sign of any water. There was no information available to suggest an ongoing problem with this model and nothing from BMW NA.
On Saturday I was caught in the rain again and within minutes the stalling was enough to cause me to cancel my plans to tour all weekend and head for the dealer. A real let down.
Water is backing up into the evap canister and the fuel tank can't breath. There is a problem with the vacuum system that could not be resolved. A drain tube was added to just divert the water, but the mechanic was NOT comfortable with all the loose ends and I was asked to leave with a DEMO F800 GS (and not ride in the rain).
1300 miles and my new GS is in the shop and cannot be repaired.
The Dealer will contact BMW NA on Monday and determine what the "fix" will be. I have seen as many posts explaining that the problem does NOT exist as I have seen where the problem does exist.