A BIOS update should be avoided for minor issues like this due to the risk of irreversible adverse side effects or worse. I suggest that you turn off all timers in your power plan,change all settings to sleep (none to hibernate) in your power button plan, and UNcheck fast boot. Then shut down Windows normally. Turn it back on again to see if it resolves the sleep issue.

If it was mine in this situation, I'd probably download and install Driver Booster freeware to see if it can pick up any new drivers on line that might resolve this issue.

Other than that, I'd simply change all settings in the power button plan to do nothing when the lid is closed. The hall lid position sensor will shut the screen off anyway. Screen is the biggest power drain. CPU/GPU use very little more power idling than in sleep mode. Or with the lid open, I'd press FN+F6 turn off the screen. Opening the lid or touching any button will turn the screen back on.

Any other method to resolve this issue on your G3 --- such as a full factory reset --- or a BIOS update --- would not be worth the effort or risk to me. But it's not mine, so you'll have to make the decision. Sorry I can't be of more help on this. 😑

Good luck. Please let us know if anything pans out.