Can’t Upgrade Endurance to 6 Star (potential bug?)

Hello, I am having what I think may be a bug with my endurance. I completed the 6 star event and earned the blueprints needed along with the 500k ship materials. However, when I go to upgrade the ship I keep getting an error which is attached below. (Insufficient material). When I click on other ships like my hounds tooth which is ready to go to 6 star I get the prompt to upgrade it which leads me to believe it’s just the endurance that is bugged. I have tried logging in on the pc client, restarting both my pc client and mobile game. Upgrading something else then trying to upgrade the endurance again and nothing has worked. I’m very fed up with it and would appreciate anyone who has any idea how to help me. Thank you!