I am unable to say whether Jaksta Media Recorder can successfully record a meeting from zoom.us
Recording live streams can be tricky anyway, and then video conferencing software/applications generally have extra security protocols in place which make it even harder.
If you were going to attempt it I would also suggest using the latest update of JMR. If you are running an older build (especially Version 1), then your chances of success will be far less likely.
What probably would be more likely to work is an application like Jaksta Screen Recorder, which will record the video rather than the stream.
It should also be unaffected by any security/blocking features of the site and stream.
Will Jaksta Media Recorder record a meeting held via zoom.us?