I got my replacements from Brew Hardware:
https://www.brewhardware.com/product_p/ballpostgas1932.htm
https://www.brewhardware.com/product_p/ballpostliquid1932.htm
I guess they aren't technically shorter, but the threads aren't cut as deep as my earlier fittings, resulting in the same effect where they don't bottom out. The shape inside too, where the O-ring lands, is also different than my earlier fittings, and there's more "flat" for them to hit. When you screw the Brew Hardware fittings in place you can actually feel the O-ring contacting them slightly, even before any tightening occurs. And when the O-ring compresses it his a flat area, not just threads.
When I say "earlier fittings" I'm talking generic fittings form Amazon, the universal replacements. I ditched every last one of them. I've got the Brew Hardware fittings on everything now. These are the ones I mentioned are working properly for me across the board and even just finger tight creates a seal. When you wrench them into place you don't have to go until they can't be turned anymore, something just past snug is plenty.
