First, make sure that your Gateway Puck is reporting to your Flair system by confirming that it is on, online, and connected to your Flair system.
After confirming that your Gateway Puck is reporting, turn on Setup Mode for a few minutes. This can be done by clicking Home Settings → Flair Devices and flipping the Setup Mode slider to on. Wait up to five minutes for all your devices to enter Setup Mode. Confirm that all your Flair devices have been added to your home before turning Setup Mode off.
After turning off Setup Mode, refresh the data in the App (either by refreshing your browser or closing and reopening the App) to confirm that your units are visible.