Transcoding Quality and bitrate slider inaccurate after latest update

After updating, I'm getting order of magnitudes less bitrate when transcoding, incompatible with what the quality slider in "Encoder - basic" claims it is doing.  For example, asking for 100 Mbps according to the slider gave me roughly 1 Mbps.  These are stereo videos, attempting to encode with H.265 / NVENC option on a GTX 1060.  This all worked fine before the update.