[kadoban]

I guess if you let it run for a long time it should converge on a first move?

I don't think there's a real fix for the issue, unless someone effectively solves chess someday. Otherwise your win/loss is fundamentally based on the imperfect evaluation of a particular engine.

If it's really just the nondeterminism that bothers you (which is fair enough, preferences vary), there's engines that either are deterministic or can be made so with settings.