Bitrate and quality

Hi, there is the next problem. The original video has bitrate from 5 Kbps till 15 Kbps, and higher. The source is Premiere Pro, codec h264, 1920x1080. When I download these videos to Kaltura with the several options of quality, in player bitrate becomes low and quality isn’t well. Why exists such a problem? Maybe I have to output video with other settings in Premiere Pro? Or should change options in Kaltura? If so, where is it? Could you explain settings step by step. Thank you!

Hello,

Can you share a link to the source so we can inspect?