Do you use any triggers for STHM? For my house, I have a morning automation at 4 am to turn on the coffee maker, turn on a few interior and exterior lights and set the location mode from Night to Home and for STHM to disarm. When both my wife and I leave, the mode changes to Away and STHM switches to Armed (Away). Either of us returning switches it to disarmed and the mode to Home. When we go to bed at night, we either tell Alexa goodnight, which triggers a routine to control a simulated switch or we press a button. That simulated switch or button press then triggers an automation in ST to change the mode to Night, turn off all the lights, lock the doors, and puts STHM in Armed (Stay).
Create 3 Automations to have STHM follow with location mode changes , like so: