Thermostat Home, Away, Sleep modes, effect on Fan

When my thermostat is set to sleep mode, the fan hardly seems to blow at all. When set to home it blows much better. When away it hardly blows again. Without the fan up to full speed, the AC can never cool the house. I can’t find any documentation that actually states the effect that sleep mode or away mode or home mode, has on the fan speed and the AC’s capability of cooling. Who can share what is really going on with the furnace and AC units when the thermostat is in these different modes?!

I ask because the default temperature I set seems to be ignored or the AC is incapable of cooling to the temperature I set. But I noticed the fan comes on stronger or weaker at different times depending upon how things are programmed. But I need verification to understand the actual operation of the thermostat and the impact it has on the fans and the activation of the AC unit.

Do you have a variable speed or two stage fan AC unit?

My fan speeds are all the same until the very last couple seconds when the coast to cool kicks in and the fan speeds up after the compressor kicks out.

Do you have schedules set that have temps different than the programmed Preference defaults? If you set schedules in the past, those schedules grabbed the default Preferences from the 3 states at the time they were programmed and locked them into the schedules. If you then change the 3 state preferences, the schedules do not change. And, schedules will always override preference. If you change your preferences, you also have to reprogram all your schedules to grab the new Preferences for the 3 states.