Thermostat not getting power and won't turn on fan or AC. Does have power with batteries, still no cooling
Ended up finding out what was wrong with it, posting it here just in case someone else stumbles on this. Since I'm in a condo, my furnace was installed in the ceiling. It also has a safety overflow switch installed: https://www.diversitech.com/en-US/item/id/2070

When the person installing the furnace popped that switch on he thought he would make it face the ground so you could see the light. But it's supposed to only trigger when the pipe is full, and condensation will always be drawn towards the ground due to gravity. After a few years enough condensation had built up to trip the SOS but not enough to drain through the pipe. I flipped it upright and everything kicked back on.