The Nintendo Switch is surprisingly sturdy, but this is a common problem: joy-cons that still click (and oh, how I love that click) and snap to the console, but slide off when they shouldn’t (e.g., right in the middle of an online game match).
The cause is a plastic latch that erodes slightly with use (or maybe after it gets jammed on the backplate when you mis-connect it). There is a cheap replacement for that latch that you can order here†.
The replacement latch is made of metal (which should have been Nintendo’s original choice), and several videos (like this one) show how to replace it. No soldering is required, just some careful screw removal and disassembly.
With the usual caveats (you do it on your own risk, it voids your warranty, etc.), here is how it went for me.





