Have the provider show the actual setup
Get the outdoor model, all indoor models, and controller details. Ask which head or controller has priority, which modes can run together, and what the display does during a conflict. Have the provider show the difference between Auto operating mode and Auto fan speed. Keeping the fan on Auto does not necessarily mean the unit chooses heat or cooling automatically.
Request the exact user-manual sequence for changing modes. Do not use breaker cycling, installer menus, or wiring changes to force a change. Ask which normal delay is expected after a switch and which behavior calls for service.
Make the daily choice clear
We would choose the needed mode from how the occupied rooms feel and what the household needs, within the equipment's operating limits. On a mild afternoon, you may not need active cooling everywhere. At night, rooms that need heat should have an agreed heating setup if the system requires one shared mode.
Have the provider write a short guide for your configuration: which heads to set, which normal controls to use, and what to check if a head waits instead of running. Put it where everyone using the system can find it. If one bedroom regularly needs cooling while another needs heat, tell the designer. Ask whether controls, room conditions, or a different arrangement is needed rather than accepting a permanent conflict as the whole solution.
Check with a separate room thermometer if the displayed setting and actual comfort disagree. Record the mode and other heads' settings when a problem occurs. A standby indication is useful evidence, but it should not be treated as a fault without the model's instructions.
Your next step: Request a demonstration and written shoulder-season routine for your exact combination. Use that routine, and seek service when operation falls outside its documented behavior.