Tycho,
We don’t use hardly any stainless steel valves, but bolts yes.
Assuming we are talking Danfoss, standard valves have had stainless bolts for quite awhile.
Danfoss say to tighten to “X” torque, we are dumb & tighten using our best judgment on the day.
Mee usually alway use anti- seize on bolts as well.
Have not heard of any issues at all.
Since Danfoss went back to gasket seals from “0” rings, if not tight enough, maybe some gasket relaxation?
Stainless valves may be more prone to expansion & contraction, don’t know.
Why not report to supplier as serious safety issue if it concerns you (maybe that’s why you are confirming your observations).

https://www.assda.asn.au/blog/221-st...less-fasteners