openhab-core: [REST] Event source connection broken

There are a few posts in the openhab forum that after a while permanent devices running MainUI get disconnected from SSE. This was expressed by Yannick here and by Rich here. And while I am writing this a user was able to get a console log from the tablet device:

ERROR: The connection to http://<MY_OH3_SERVER>/rest/events/states was interrupted while the page was loading.
WARNING: SSE error
INFO: =!= Event source connection broken…

I also found out that the disconnect happens when browsers are calling Google‘s safabrowsing API. At least Chrome, Safari and Firefox are using this Google API and do call to this URL: safebrowsing.googleapis.com

Is there anything more we can contribute to find the error?