MJPEG frame detect not working

[corrpel]

Hello,
I am using MJPEG because of the lower delay and better quality.
Using MAC OS 15.3 on MPA M1, safari browser. What i am seeing using activity monitor app to check received bitrate is that the frame detect feature is not working.
The bitrate is constant and does not go lower when idle, meaning no change on screen. There is no difference with it on or off.
Can you please check?
imgv: 1.3.0
appv: 2.1.5
Thank you.