What it says on the tin. Any attempt to changing items in the wargear section will have your screen show whatever you changed to has been equipped (such as an ogryn now holding a stubber instead of a ripper, the items panel on the left side of the wargear screen will change accordingly too), but fully exiting the wargear tab back to the ready-up screen will revert the change, and opening it again will show your character as if you never swapped any of your items prior to opening the wargear screen for the first time during the ready-up screen. The wargear change will only go through if you complete, fail, or disconnect during a mission.
Steam name is “Bitz”, custom ID being “ysdhey”.
This constantly happens, 100%, every time.