Disconnector?
Sounds like a disconnector issue to me. A strip down and thorough cleaning would be my first step; a little crud in the disconnector slot in the slide rail (right side) could very well cause something like that.
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The disconnector is incorporated with the trigger bar, thusly:
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Here's what it looks like in person in operation:
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When the slide is not in battery, the bar is pushed down by the disconnector so that the hook on the rear end won't engage the sear. When it is in battery ... or almost in battery... the tab lifts up under spring tension into the radiused cut out in the slide rail and allows the bar to move into position to engage the sear.
If, for whatever reason, you are not getting a solid, consistent sear engagement and have to fish around for it (double pull etc.) you have what I would consider an unsafe condition and that pistol should be grounded until the situation is corrected.
As an NRA Range Safety Officer I would not allow you to shoot it on my range the way it apparently is now.
I posted an extensive illustrated guide on Czech-O-Matic tear down and re assembly here a couple of years ago which a lot of people liked, but which the mods felt did not merit posting as a sticky (despite several requests to do so) and it fell into the abyss of archival obscurity. Good luck finding it now.
At least one other fellow has put up an online tutorial. As far as I know it's still out there somewhere.
You want to study up on this pistol before you go tearing it apart - but that's what you have to do if you are going to get it really clean and inspect for cracked frames, slides etc. which have been an occasional issue with this particular sidearm.
If youre not comfortable doing your own teardown, cleaning, diagnostics and trouble shooting I would recommend you take it to a competent Gunsmith.
