Substance in Maya 2022 v2.2.3 - not storing all parameter values

Hello,

I am using Substance in Maya 2022, v2.2.3. I've applied a Brick Generator in my scene, brick_generator.sbsar, from the Substance 3D Painter starter_assets.

It's only saving some of the parameters in my Maya .MA file. When I re-open the Maya scene, most of the parameters are reset to their defaults.

I am able to create a Preset in the usual way, but that doesn't help me. I'm losing data here.

Is there something about this SBSAR that doesn't conform to spec? It only has a single floating point Output, none of the usual PBR stuff like Base Color, Roughness, etc.

I haven't had time to test other SBSARs yet.

Thanks

Aaron