iPhone 16 Pro shortcut to resume standby mode

Just moved from Android to an iPhone 16 Pro and having trouble with Standby mode.

I want to use the phone as a night clock (as I have for many years) and I'm finding that after a few hours the screen goes off.

Always-on display is enabled (extremely misleading description!).

The issue is very widely reported and I think the problem is with the charger, in that I assume the power supplied isn't consistent. I have the Optimised charging setting enabled, and it seems that every time the charging is interrupted by the phone, Standby goes off. It stays on when wired charging is used, but I don't want that to be a permanent solution.

I'm not buying another charger (I already had to replace the one I've used for years because apple require the phone to be landscape) and I'm hoping there might be a shortcut automation that will re-trigger the Standby mode.

Any suggestions?