I have long had a standard, still like new, H-K P9S target pistol (1980's vintage) which is a sheer delight to shoot. It is, by far, my most accurate 9mm with its fixed barrel, roller delayed slide, and screw adjustable target grade trigger.

It also has a peculiarity that has had me wondering for many years as to whether its uncommon safety behavior is amiss or if it is functioning as expected. That is, if it is cocked with(or without) a round in the chamber with a magazine in place and the safety is engaged, IF one then elects to pull the trigger the consequence is a really fully disabled firearm. Simply reversing the safety does not return functionality. The slide must(somewhat challenging) be removed and tediously replaced to re-enable the weapon's full functioning. Is this the normal expectation for this pistol or is something amiss?

I have never had the unsettling experience of encountering this, only experimentally, but were it to happen in some stressful circumstance it would certainly be discombobulating. Has any one else encountered this as a known 'feature' or is it a correctable(or otherwise) bug/fault?

If I'm following correctly, it sounds like something is off compared to my P9S functions.

If I rack the slide, it is essentially in a single action-type state. If I put the safety on and pull the trigger, that is the only way to "decock" to a double action state. There is another peculiarity in that it can be in the double action state and two presses of the thumb lever put it in single action. I don't recall ever being in the state that it is locked up like you mentioned.

You might correspond with https://www.teufelshundtactical.com for armorer info.

You can search www.hkpro.com for P9S threads also. I was just there and saw several threads on P9S operation. There are about a dozen really really really informed H&K guys there who are very helpful, like the people here.