gbholzer on Dahua DVR channel encoder bit rate type issue

Hi,  I have a 8 channel Dahua tribrid DVR with 4 cameras, 1 is CVI and the other 3 are IP.  These are used to capture vehicles coming into our neighborhood.  I notice at times that the image is good for the first frame or two, then gets pixelated.  We do not have a great internet speed on this connection and I was thinking of changing the encoder bit rate type of the cameras to VBR from CBR to help maintain the video quality, but my changes do not save. 

So two questions, first will changing the bit rate to VBR help my motion images?  Second what is preventing this change from being saved?

My camera encode settings h264, 1080p, 5fps, 2048 bit rate.

Thanks,

Gary