So, this is going to sound really weird, but: Open the web inspector, switch to the Application tab, click "Service Workers" in the left sidebar, and unregiste

So, this is going to sound really weird, but: Open the web inspector, switch to the Application tab, click "Service Workers" in the left sidebar, and unregister everything that shows up. My understanding is that this behavior is caused by an old version of their service worker which they've had a hard time getting rid of.