I am also seeing this exact same issue.
I have a duplicate app made for our test server that is UNPUBLISHED and the deauth ALWAYS WORKS (sends a message to my server, and my server responds appropriately) however the real, published production version of the app, doesn’t seem to work at all. I have thoroughly tested this with logging/tracing, and I am convinced Zoom is simply not sending messages to my server for the production app, even though the Deauth URL is correct.
I was told by email “Please regenerate your Publishable URL and reauthorize to see the updated Deauth URL in use.” however this does not seem to be fixing the problem anymore.
I really want Zoom to sort out the interface and fix the Deauth url to make it very clear and testable for developers.