Today's update, 23.4.0, Build 44, has broken the Review Panel. It just displays as a blank panel. Switching to CPU only changes nothing, clearing media cache, i.e. nothing. It was working fine in the last build.
Yes, the last couple of updates broke all the panels in the "extensions" menu on my side, (I have several plugins: Premiere Composer, Pluraleyes...), these are called CEP panels as I remember. (win 10, build 45).