Chosen Solution

When I put on a new switch it didn’twork, it was onlytwo black wires, no gfci was tripped, I’m stumped Update (06/04/2022) I am starting to think it is the splice, but I’ve also decided to get a double rocker to separate the fan and light function, this would seperate the splice as well, what do you guys think..?

How many wires are within the switch box, that is besides the two Black wires that go to the switch. I’m suspecting the splices of the other wires needs to be checked.

Here’s a dual switch setup with a light and fan

It would be helpful having a MultiMeter to double check the switches wiring. Also check your fuse/breaker that its on. And off when you are checking the wires so you don’t get zapped!