@carl Same thing happens on my Pixel 3a. And agree, it is worth it to re-enable after each reboot.

Late to the party here, and this is my first post but I came across this during setup of UT on my recent Pixel 3a acquisition.

• From left side tray select "System Settings" (gear tool).
• Select "Gestures"
• Slide "Tap to wake" on. This enables double-tapping anywhere on the screen to wake the device.