Ok.
I installed new F1M2 from here
https://www.mediafire.com/file/1uup0pew04bqjuu/Mitsubishi+F1M2+Pete+v8.7z in BAT 3.6.1 as separate mod.
So, now I have two planes in my air.ini: F1M-Pete (default in BAT 3.6.1) and F1M2 (from separate mod) and accordingly two planes in my plane.properties: Mshi F1M2, 1941 (default in BAT 3.6.1) and F1M2, 1940 (from separate mod).
When I tested them in QMB, F1M2, 1940 from separate mod engaged the enemy as a Fighter without any problems !
The default BAT Mshi F1M2, 1941 still acted like a Scout.
Conclusion!
No particular remarks. Everything works fine in 4.09 !
If you tested it in 4.09, so your F1M installed as separate mod. Right?
I suppose that there is TypeFighter in java code of F1M separate mod.
And that's why everything works fine for you.
While TypeFighter is missed in the BAT java code ...
So far I am not able to use the class resolver to see the contents of the class files...
But I found Decompiled Classes of BAT Expansion Pack 12 "World at War" here:
https://www.sas1946.com/main/index.php/topic,39674.msg331524.html#msg331524There are two java files for this plane: F1M.java and Pete_v1.java.
In Pete_v1.java I found this line:
public abstract class Pete_v1 extends Scheme1 implements TypeSailPlane, TypeScoutIn F1M.java I found this line:
public class F1M extends Pete_v1 implements TypeSailPlane, TypeScout, TypeDiveBomberI did not find any TypeFighter in both files...
Maybe this is the problem?
Sorry for my perseverance ...