737NG Dual Pilot Go-Around Error

I've been using the PMDG 737NG since it first came out so I know it pretty well, I thought and I think it's a great MSFS product.Today I found an error with a dual-autopilot go-around. On a CAT IIIA approach at minimums, I executed a MAP by pushing the TO/GA button twice, twice to get a full thrust go-around. I noticed that the B autopilot disengaged, the A remained on, and there was no autopilot ROLL controll of the airplane with A on. The go-around should have been flown with duel-autopilots up to MCP altitude where B autopilot would disengage.I did another CAT IIIA, except this time I pushed the TO/GA button once and the go-around was flown correctly as a duel-autopilot go-around.Searching, I could not find any disscussion of this error. Is this a know problem?Thanks,John Floyd