Then I found another post talking about “Advanced Settings” (ADC T3000 Humidity Control) but I don’t see those settings in the ADC app or website
Per that post, the user was having trouble getting the rule to apply on their thermostat. They resolved it by deleting and re-adding the thermostat.
Have you tried that in this case?
The advanced settings are found by logging into the Alarm.com website and clicking on the thermostat card. Click Advanced Configuration at the top. There you have access to 3 tabs, User, Advanced, and Installer.
The advanced tab will show the relevant humidity differential. That just means the thermostat won’t run the ac more than that far below your target temp in order to dehumidify.