tbh, we are all probably on the same boat here! I did get stressed and at one point agreed with you on everything BUT! I actually had to stop and relax for a few days and come back to this and the problem is actually rather simple! There’s a reason why these guys won’t give any further hints, because the answer is really rather simple!
Hands up red as I am very guilty when it some to looking up answer when I gets stuck, I will do it rather than try to go back, recap myself and figure out solutions. But the in real world, if this is going to be your job then you’ll have to be able to do this yourself. These guys are not going to be there to help you!
It is simply what it said on the tin, they didn’t want you to do any coding, they just want you to find the problem and fix it (AKA “replace”), it’s actually pretty simple!
This is a hint.