Locking the screen now counts as "exiting" and app for an automation shortcut

I have an automation shortcut setup to turn on DND when I open my meditation app and then turn off DND when I close the meditation app.

Before iOS 18, I would open then app which would auto-enable DND, start the meditation timer, and lock my screen. the phone would STAY in DND. Then when the timer finished, I would unlock my phone and close the app which would then turn off DND.

Now with iOS 18, I open the app which turns on DND, but then when I lock my phone it turns OFF DND. When I then unlock my phone, the meditation app is still open but it does not enable DND. So it seems that locking does count as "exiting" the app but unlocking does NOT count as "opening" the app.

This new behavior unfortunately now makes that automation shortcut useless. Since it's new and erratic I'm guessing it's a bug and not an intended behavior?