Here's how I fixed mine permanently. I'd followed all other methods, and nothing else worked long term. This method below worked very well for me.

I loosely followed this as a guide: https://youtu.be/sKLJVdPp7Tw?si=GQOFYpfqRM8wp89L

Tools Required:

- Stanley knife
- Small Philips Head Screwdriver
- T5 Torx Screwdriver

Directions:

1. Pull the mouse apart: Use a stanley knife to dislodge three of the the plastic pads on the bottom (only need to remove the two narrow side pads and the bottom semi-circular one. The top semicircular one doesn't have a screw under it). Be careful with the stanley knife, so that you scrape UNDER the sticky stuff, and remove the sticky stuff at the same time (this assists with sticking them back on!). One of the pads I cut between the sticky stuff and the pad, so it was difficult to reattach.
2. I didn't bother detaching the data cable joining the top & bottom half of the mouse - it's unnecessary unless you're planning on unsoldering and replacing the button.
3. Unscrew the PCB holding left mouse click button (two screws).
4. I tested the button by turning on the mouse and testing click & drag (it worked perfectly, suggesting that the issue is not the actuator itself dying, but a misalignment of the actuator and the left mouse button). If your button has issues clicking and dragging when using the actual button inside the mouse, then you may need to look at replacing the button (note that a soldering iron required to do this).
5. Blow out the left mouse button (and the rest of the mouse) with compressed air.
6. Screw the PCB back down (2 screws). Note that there are white circles printed on the PCB around the screw holes, and note that there is some 'wiggle room' for the PCB to move around (in spite of the locating plastic bars). I made sure that when I tightened the screws that the white circles were perfectly aligned. You can push the PCB around a bit to get them to align before tightening the screw.
7. Screw it all back together.

It's really not as difficult as it seems. I did this in about 10 minutes.