I have been having the same exact problem. It`s not the setup of the front derailleur. There is only so much you can do with the setup of the FD. I bought a new frontring which eliminated the problem... for like 10 rides, then it started to happening again. I tightened the spring in the RD but with no luck. Then I switched from SRAM chain to Shimano and now the problem is gone. I didn`t have this problem earlier either when I was running a KMC chain. Seems the SRAM chain is a bit stiff sideways which makes it drop the chain in certain gears.
I have a friend who had the same problem on SRAM Red and switched to shimano chain and, voilà!
I had to get of the bike several times in my last race so I know the feeling, maybe a clutch type RD will work also. Like the type 2 SRAM. If this problem comes back I will just order a new XTR group right away