I think I might hate Miatas

Bought a CARB compliant cat setup for my wife’s Miata and attached it all up. I attached this to the header (only part that didn’t get swapped). Upon attaching, the gasket (Manifold/Downpipe) had a leak. Was a bit annoying, but Finally got it resolved by using a better gasket. I fire the thing up after smoke testing it to be damn sure it’s all good, and now there’s leaks coming from the MIDDLE of the header ( when looking at the header from an above view, in between the 4 pipes). Never even noticed it before any of this crap and was never a problem. What is going on? And what would yall reccomend I use to patch it up? Seriously trying to avoid swapping headers but the leak is in the worst possible spot I can think of… any ideas help.