Output file much higher bitrate than set

[Roberto Etcheverry]

I'm creating a series of videos, the client wants them at 500 kbps. I have the output video set to CBR and 0.5 Mbps. I've rendered about 70 videos in the series with those settings with no problems, then a couple days ago I rendered a video and the file size came out much bigger than expected. When I checked the file in a player it was at around 3.5 Mbps.

I've tried exporting different videos, on new projects, both on premiere and media encoder, and even uninstalled the entire adobe suite, used the cleaner and reinstalled premiere, and I keep having the same problem.

[Mike Dziennik]

I don't know why this might be happening, but have you tried switching to Software Encoding, rather than Hardware Encoding? Have you updated any drivers recently? Updated Premiere?