I just went thru a similar issue with my PCR. Now, that I have a small collection of CZ slide stops, it is easy to see the differences. The length of the shaft ( that goes thru the frame and touches the stop return spring) is one critical dimension. On my PCR, this was longer than a 75.
Next the tab that grabs the magazine/slide stop notch also varies. I have seen this item mismatched, and create an issue where the slide either wont move rearward more than an inch, or where the slide stop is not working.
CZ makes several, and I am also sure that some "wrong" stops can be modified to work. I almost went that route while waiting for the correct one to arrive.
Good luck, and glad to hear it works in the 97
Rich