Select gun and it goes to "5B", select Amraam and it changes to the Amraam radar mode, but remains in 5B.   
Cycling the Bar setting increases it +2. Got it up to 103 before I got bored. 
Also the scan width gets screwy, 1122 degrees wide at one point I think.   
If you select Sparrow it sometimes resets to 4B, which then is retained if you select Amraam.   
Edit. Reverted to 2.5.5 - normal behaviour. 4B is reset when selecting Amraam.