There was a thread a couple of weeks ago, in the film slr forum, about someone who had a Pentax SF1 and a Quantaray 28-90mm zoom lens that would not AF.
https://www.pentaxforums.com/forums/pentax-film-slr-discussion/119112-do-i-have-right-lens.html
I happened to have that exact combination, although it turned out, I had never tried the two together before. The Quantaray autofocused perfectly on my K10D, and on a Pentax ZX-60 film SLR, but not on the SF1. Other AF lenses worked perfectly on the SF1. I attributed the problem to the age of the SF1. It was, I believe, the first Pentax camera to use the current screw drive AF system.
Apparently, some quantaray AF lenses don't communicate properly with some Pentax cameras. Perhaps, your combination is one that just doesn't work.
I was never able to figure out exactly what was different about the SF1 or the Quantaray, that made them incompatible, but it clearly seems to be the case that some combinations simply don't work.
I know this isn't what you wanted to hear. Good luck.