Power button double-tap action isn't triggering on S10

I'm trying to remap the power double-tap action on my Samsung Galaxy S10 using Tasker.

I've seen the video on doing this with the Bixby key but am not having luck reproducing it with the power key.

- I've turned off the "Quick launch" toggle in the stock S10 camera
- Got the popup asking if I wanted to set tasker as the power double-tap action (and restarted the phone as requested)
- I've tried the adding the custom setting to make sure this persists at startup as per here

All to no avail.

- If I select the Tasker Secondary Action app from the app drawer it does what I've configured it to (flashlight, just to test)
- Double-tapping the power button from the home screen locks the screen on the first tap.
- Double-tapping the power button from the home screen turns the screen off and on again.

Feels like it's not recognizing the action as a double-tap and just processing as two single-taps. Any help?