2nd stage hose bottoms out on apeks xtx50 threads

[FwaScubaDiver]

So I have an apeks xtx50 for my primary
I have a swivel between the 2nd stage air hose and my reg.
The female part of the swivel mounts to the xtx50 and before I can feel resistance, it bottoms out (the end of the female meets the base of the male threads of the xtx50
I’ve had the o-ring replaced and still same issue. It is torqued correctly but I fear it may loosen up over time due to movement, vibration, etc
Is it normal for the female to bottom out w little to no resistance?
Looking at the female end of the hose that attached to male end of swivel, it looks to be same length as the female off the swivel and I think I would encounter same issue should I remove swivel
thoughts?
Thank you

 

[Shabaday]

What brand of swivel?

 

[FwaScubaDiver]

Swivel has no markings

 

[-JD-]

Without a swivel for the moment...

The 2nd stage hose seals to the smooth inside bore of the 2nd stage barrel (exposed threaded part.) At the hose's end, there is the outer female-threaded sleeve which freely swivels and sole function is to hold the hose into the 2nd stage. Rigidly attached to the hose with the crimp is an inner male shaft with an oring groove and oring (around the exterior of the shaft) which slides into the 2nd-stage barrel to accomplish the seal.
The outer threaded sleeve needs to either stop with its outside end against the jam nut (further up the barrel of the regulator) or with the inner end of the sleeve against the end of the 2nd-stage barrel. This allows it to be torqued a bit to prevent loosening. On mine, I have seen the end of sleeve to jam nut interface so (speculation) that may be the "standard", or at least, more common.

The swivel just rereplicates the hose-end and barrel-end forms with a bend in the middle.

Long story short, your experience is normal.

The hose sleeve bottoming against the jam nut, makes it critical to be sure that the jam nut does not loosen as well when loosening the hose or you can loosen the the air barrel in the 2nd-stage housing and possibly even cause damage by forcing the barrel to rotate. Best practice is to use one wrench to hold the jam nut from rotating ("braced" against the housing for reference) and another wrench to loosen or tighten the hose sleeve nut.