I'm trying the unregistered version of Bandicam and i'm noticing when I set the rate control to constant bit rate and set it to 120000 kbps the final video doesn't adhere to the bitrate set. It's much lower (21789 kbps). Is this a bug or is there something I'm doing wrong?

I'm using version 4.5.5.1632. Recording MP4 at 23.976 constant frame rate, H264 (NVIDIA NVENC), 120000 kbps, profile high 4:4:4. The same problem happens when I use x264 (CPU).

My pc specs are,i7 7700k 5ghz
16gb ram
1080 ti
Windows 10