Extremely high bitrate value in the REMB message

Hey,
Before a week, I opened a new issue about a specific video which is not playing when I stream it through Janus using ffmpeg. (Screen recording video is not played using janus and chrome, throws a lot of Nack errors).

I added a ?pkt_size=1300 parameter to my ffmpeg streaming command but it did not help. I tried to sniff the packets and I have noticed that in that specific video that does not play, the REMB message contains a huge bitrate value: 15442624. Other videos I have checked sent a more reasonable bitrate value in their REMB message, such as: 4523200.

I guess the huge bitrate may cause the very high amount of nacks. Could you please help me understand, what causes to send such a huge bitrate value in the REMB message and how can I change it?