It looks like the 3.3.5.1 update has introduced a bug that overcompensates brightness in the IPR window for C4D S22. Looking at the release notes, this may be related to the follow fix:
My assumption is this fix may have leaked into non S24 versions of C4D. I am working with C4D S22.123 and Aces color management (OCIO 1.0.3)
Screenshots attached for reference. Test scene rendered both with 3.3.5 and 3.3.5.1. Notice IPR is over-brightened in 3.3.5.1.
It is indeed a regression caused by the previous fix. Seems like I was not careful enough to touch only the S24 code path. Sorry about that, will be fixed in an upcoming release soon.