Shortcuts automation fails to open Safari "because the iPhone is locked"

Hello,

I'm new to using the iPhone and I have a Shortcuts script setup that runs Safari.

When I run this shortcut manually, it works perfectly.

But when I setup an automation to run it daily at a given time, I always get a notification that it failed to run:

"At xx:xx, daily" encountered an error: Couldn't Open "Safari"

"Safari" couldn't be opened because the iPhone is locked

Obviously when this happens I am not using the iPhone. If the automation happens to run when I am using the phone, then it works just fine. But this is pure luck.

Other iPhone users on a popular Internet social media forum report they can run this Safari shortcut just fine and never see this error. I have a (nearly new) iPhone 13 Pro running iOS 15.1.1 and it doesn't work via daily automation for me. So I am stumped why it works for some people but not me. What am I missing on my iPhone somewhere?

I've tried rebooting and obvious things like checking the privacy settings on the shortcut but I am still stuck.

Is there any way I can get this to work? Or is it simply not possible to run Safari via Shortcuts (daily) automation?

Any help/clues much appreciated! Thank you.