There’s a thread on glycol settings already. I’m camping and on my phone, so forgive me for not looking it up.
You’ll want to set beer-to-fridge to all zeros. You’ll want to set the cooler pwm period to 60 seconds and adjust Kp for your situation. Also reduce the minimum cooling time to a few seconds. It is key to limit running the pump to just a few seconds at a time. The glycol cools really quickly and it can take a while for the temperature change to reach the sensor.
It might even be needed to use a period of 600 seconds with a Kp of for example 4. So that with a temperature difference of 0.5 the pump and will run for ( 4 * 0.5 / 100 ) * 600 = 12 seconds every 10 minutes.