I heard of a post where somebody in a tank mentioned that their guns reset every time they go back to cockpit then return to guns (reset default position) well I've found a slightly different bug.
The bomb selector resets to default *every time* I hop into a gunner position. This is especially so if I go to bombsite, back to cockpit.
I was in the rear gun on an SBD recently and it reset every time I went back to cockpit (2x100 1x250-ish)
Then I was in a TBM and I think it did the same thing (exact memory is fuzzy).
Have not tested all vehicles offline (nor do I have the time to, lol).