Further apologies in that I'm not willing to re-break my laptop to pull up a DxDiag from the pre-fix or broken states, however I can dig up version numbers!
- The laptop is an Acer Nitro 5, model number AN515-44. It has an AMD Ryzen 5 4600H and an Nvidia GTX 1650.
- The old working state used the iGPU drivers supplied by Acer, dated 2020/11/06 with version number 2.84.0.51 and the Nvidia driver version 461.92
- Updating the Nvidia driver further than that would break Vulkan, as previously described.
- I sought out drivers directly from AMD, and used their software package to install iGPU driver version (pulled from Device Manager, as hilariously I can't find it in their software) 30.0.13025.5005 dated 2021/10/05
- I updated Nvidia drivers to 496.49 and subsequently 496.76, both now working flawlessly so long as Acer's software doesn't do something stupid like revert my iGPU driver...