Does your dGPU work while unplugged with the old drivers?
AFAIK it's pretty common for laptops to require the power cable to run the dGPU / at full power.
You may want to look into Windows Power settings for any battery / dGPU related settings.
Here's something called "MUX Switch" from the product page that looks relevant.
![tuf.PNG tuf.PNG](/t5/image/serverpage/image-id/109446i69BF9E87E26F0A0B/image-size/large?v=v2&px=999)