@britzl I wasn’t scaling at run time, but I was scaling at build time (but only slightly). When I took off this scaling, everything worked as expected.
Out of curiosity, is it on the roadmap to support collision masks on scaled objects, or is it just assumed to not work with scaled objects? I would think there would be warning (or just not allowed) since the behavior is pretty unpredictable. Regardless, thanks for your help!