Heartbeat behaviour in different browsers

Hi all,

I’m interested in whether it’s known how heartbeats are handled by different browsers. I ask because, with the default heartbeatInterval in Safari, it seems that whatever javascript initiates the HEARTBEAT request is not triggered when the browser tab is in the background. When I set the heartbeatInterval to 30 seconds, Safari seems to now always send the heartbeat as expected.

Is this explainable? Are there other quirks in other browsers?

Best, Dan.