Looks like a SSE connection problem.
When that happens go to Developer Tools, Debug (the 2nd tab at the top), click Stream Events and check that you have events coming in. (Change some items with another device if necessary).
If you have problems, and if it’s specific to iOS Safari, then you might have some success trying this: How to Debug Websites on iPhone Safari | BrowserStack and then look in the JS console, if there are SSE disconnections they should appear there.