This was from a simple dispersion test. Very first time loading the new daily for 1.7. I made a refraction material, then clicked dispersion. Instantly it rendered wrong and then materials wouldn't change in IR after changes. As if the refraction is visibly 0 but light still passes through it despite appearing solid.
I was able to replicate this just moments later in a new file. Initially it loaded as I would expect, but after a few material tweaks, IR stopped refreshing with material changes and then it started rendering without any refraction (but with thin checked it worked fine).
Has anyone else experienced this issue? I literally can't get past one material adjustment in the new dailies.