Jean-Christophe Gueriaud:
Hi,I don’t know exactly the reason.
You can try to google nginx websocket, that’s probably a “common” problem.You can also check this link: https://mvysny.github.io/Vaadin8-push-issues/
The solution/theory also works for Vaadin 14.
I was looking for answer in google and haven’t found solution yet. Maybe my english is not enough for this…