I replayed the mission Sleepers to get the Exo-Plating Armor Mk XI on my Fed-Romulan. When I right-clicked the item, there was no option to upgrade it at all. I also tried slotting it in the upgrade window, no dice. Please fix when you have the time. Thanks.
Sent support ticket on Nov. 29, 2020 through in-game bug report tool and now a post in this forum as well.
Where there is a Will, there is a Way.