Those are the ones you have, right? Check the wiring for each function to make sure the thermostat and unit agree. Then check the configuration on the unit and thermostat to make sure it’s correct. Then run a system test from the thermostat.
You should also be able to just short Y to R to turn on the compressor.
But I’m not a professional, and I’ve never worked with anything more than a furnace with a fan. But it looks like the principle is the same.