I have the 3x3 mod added to the mining gadget, as well as a few others. By default, the laser is set at 1x1. When I shift-click to select the 3x3 option, nothing happens other than the gadget visibly moving in my hand.

version 1.6.0, MC version 1.16.3, custom pack

Have you got a key binding set for the gadget instead?

Um, no, not at all. That's totally not what I did.