[2021] Not getting Kitgun progression.

Hey AngryFacer! This issue was just fixed in Hotfix 29.10.8 :

Fixed Modular items rankup not being tracked in the Profile properly.

Looks like this was not working retroactively, we are investigate this issue.

If you want to fix it yourself, you could run a quick mission with the weapon in question and earn some XP and it should update correctly.