Left Bumper does not function when pressed.
I’m on my second Xbox one Elite Series 2 and the left bumper is failing to repsond. It still has the same click as the right, and only sometimes functions on a hard sustained press.
My experience with fixing these is that the physical switch soldered onto the board can go bad. Usually when you press a microswitch, hear the click, and it doesn’t work it means that the physical switch is bad.
If you have low temperature melt solder and a hot air station it’s a doable fix. The part isn’t all that expensive, a ten pack runs about $8-9 on amazon (search bumper switch replacement) and they’re available on wholesale sites for even deeper bulk discounts.