The throw required to trip the shutter can be a factor, which is why I have tried out cable releases for my Pentax 67 prior to purchasing, (also ZeroImage 6x9 pinhole), but your problem seems related to the nipple threading and typ. Of the two releases you have, the one on the left is a design I've never seen before, while the Nikon on the right is the more conventional. I use a beefy Hasselblad release with a taught plunger and moderate throw. Previously I used a slender and tiny German cable release with a slightly longer throw (not a problem) — just fiddly to hold onto. I checked as a matter of fine detail the nipple and threads on each release. All releases I have (there are two) will also fit my old Komuranon 90mm f5.6 fitted to a home-made 6x17. So I would surmise the problem is in the design of the cable release thread/nibble: stick with the traditional nipple design, as the Nikon shows. Steer clear of el cheapo chinese releases: the quality control can be just atrocious. Mind you, many (including me) baulk at paying $80 for a big-name release but you'd be surprised how spectacularly smooth in operation and fitting accuracy they are.