On my D610 it works perfectly. However, aperture 22 must be fixed on the lens; this ring used to be used on analogue Nikon for aperture transmission. Today this is done via the normal dials on the camera body.

I have this lens, but I don't have a D7500. According to the Nikon compatibility table, the lens is compatible with the D7500.
See: https://www.nikonimgsupport.com/eu....
There are camera programmes that only trigger when in focus. (On my D610 a round dot in the viewfinder) Is this perhaps your problem?

I have been using this lens on my Nikon D3X and D810 for a while and it works perfectly. I only used it in autofocus mode. The shots are sensational - the lens is very affordable and still offers a lot for my purposes (portraits with sharpness-blur etc.). I just looked - it also works fine in manual mode (AF-M camera position).