While trying to find out why u64view is no longer able to enable and disable the video and audio stream I noticed that it is using telnet + simulated key presses to do this. In firmware v1.37 the menu structure has been changed, so the simulated key presses no longer work.

However, there is a better (less fragile) way to enable and disable the video and audio streams. You can use the TCP command interface. More information and explanation on how to use this can be found in the manual on the read the docs website.