Poor quality in zoom meting

Description
I hosted a zoom meeting today with 50 participants.
I used the black magic atem as a webcam source. We had a wired line with 200 mbps down and 700 mbps up.
My problem is that the quality of the stream was very poor.
In the settings statistics tab i could see that our send resolution was 320x180 and fps 15 fps.
Overall cpu usage was often over 90%
On the bandwidth tab it says sending 374 kb/s

The meeting was hosted on a iMac 27 inch 2017.
3.4ghz fourcore intel core i5
8 gb ram 2400 mhz ddr4
radeon pro 570 4 gb graphics

Is this a problem with my computer, my network or with zoom?

Which version?
5.2.0

Screenshots

Hi @Lederprogrammet,

Thanks for the post. It seems like you are facing issues with our Zoom client, which is out of the scope of what this forum is for(This forum is for Marketplace Apps). Please provide feedback to https://zoom.us/feed or try to contact Zoom client support at https://support.zoom.us/hc/en-us/requests/new and one of the Zoom experts will be happy to assist you.

Thank you.