Prove thyself efficiency not working as intended

Supernaut

Step 1 : Boot the game

Step 2 : Play as Survivor in a public match equipping Prove Thyself

Step 3 : In-game, work on a gen with another survivor

Step 4 : Notice the progress bar is red, indicating there is a debuff to the repair speed.

Additional information

Really not sure if this is purely cosmetic, or whether there is a speed debuff, but I was under the impression that Prove Thyself should negate this?

Thanks in advance!