I should probably do more testing before I make a post, but oh well, someone else might know more.
I’m playing through as Amara now, and I noticed something with her Deep Well skill (+20% mag size on elemental guns) and a shock Vladof assault rifle.
Base Mag size = 40
I pull it out, Mag = 48 (as expected)
I swap to the underbarrel grenade launcher, Holds 2 rounds (expected)
Switch back to rifle, Mag now has 40, have to reload the gun to go back up to 48.
I’m not sure if this a bug unique to Amara’s skill, or was something recently introduced (don’t have time to test right now), but after a long time playing as Moze I never noticed this happening, and I used a lot of Vladof guns along with mag ups with her.