Is Sentry mode set to be off at your Home location? (Home location as set within the Tesla Model Y's Navigation system.) Also, if you have purchased Full Self Driving set Smart Summon to be off.
Your Tesla Model Y could remain awake while attempting to connect to your home Wi-Fi network and not able to connect due to a weak or non-existent Wi-Fi service.
Unlikely but did you leave your phone inside the Model Y? This would cause the Tesla Model Y to remain in Standby mode (not sure about 26 hours though.)
Try rebooting the Tesla Model Y infotainment system. (While parked, press and hold the left and right scroll wheels for ~10 seconds will reboot this computer.)
Rarely, the seat sensor in the driver's seat is giving a false reading. The Tesla Model Y is behaving as if you were still seated in the vehicle.