Love how the senior dev said 'this is a simple fix' and it has now consumed three days of my life, two liters of coffee, and the last remnants of my sanity.

Can you share the gist of the problem? I love a good unsolvable mystery.

Talk to the Senior, and ask for help.

I once had the same thing happen, with the junior getting lost in the infra code, instead of doing a simple parameter change inthe BizLogic.

I think that means you're learning

That sounds exactly like programming! Yeah.. they're so institutionalized into their lack of self-respect that to them it's just normal and simple.

"Haha yeah let's change the entire company's tech stack, hardware and software, in 48 hours, np"

Yeah as the others said, ask what they thought the fix would be and explain where you're getting stuck