It used to be pretty typical to get 1/3 or even half bad risers. These days I don't know if I've just been lucky or if their quality is just getting better. Either way we've all had a few bad risers & will continue to, specifically the PCI-E 1X riser board:
This one isn't actually bad, but you can see how the top-right pin isn't as good.
It takes longer for my soldering iron to heat up than to do the fix:
Nothing fancy, just add a little more solder(I use Kester 63/37) & I also clip/shorten the 2 larger pins & add some heat shrink:
This helps on motherboards like the ASRock H110 Pro BTC+ where the 1x/PCI-E ports are closer together.
I started doing this on just a couple bad risers I had but now I do it to every one as a precaution/preventative. As for the 16x riser adapter I've been fortunate not to get any bad ones, however if I ever do I'm sure a similar fix would suffice
Anyway, hope this helps someone that might otherwise toss their bad risers