I'm not at all technically qualified to say, but I doubt the issues are the same. Running the latest Poser version 12.0.703 with Nvidia driver 496.13 it simply fails all Optix renders. I'm starting to doubt it worked before (and that I wasn't just using the normal GPU render), as I now can't get any scene to render in Optix, even with nothing in it other than a simple Ball shape and one light.

Helpfully, today Poser is writing the error to the Log file whereas it didn't yesterday. The part where the render fails is the same each time:

SuperFly: OptiX error OPTIX_ERROR_INTERNAL_COMPILER_ERROR in optixModuleCreateFromPTX(context, &module_options, &pipeline_options, ptx_data.data(), ptx_data.size(), nullptr, 0, &optix_module), line 411

It's always line 411. The same error, other than the line number, appeared in the Blender bug reports early last year: https://developer.blender.org/T73533

It was suggested there to clear the cache from Appdata\Nvidia\OptixCache, but as with the person who added said bug report, it didn't result in any changes here in Poser either. Reinstalling both Poser and the Nvidia drivers has not changed anything either.