P-38 CoG issues?

It's written many times that P-39 suffered some center of gravity issues when nose ammo was expanded. Were P-38s encountering something similar?

The P-39 was only about a 7000 lb aircraft, with only it's major armament forward of the center of gravity.
The P-38 was a least twice as heavy, had both of it's engines, and all of it's armament forward of the center of gravity.

The percent of change in the center of gravity between full ammo and no ammo would be a lot greater in the lighter P-39.

There you have it. You need to shift more then a few pounds to upset the trim on monster size fighter aircraft like the P-38 and P-47.