When the blue exclamation mark appears it means that data broadcasting is in progress. In other words another user changed data that you are or have been looking at. So it will invalidate your cached data and if you are looking at the record that is changed it will update the form data as well.
But a 30/45 sec wait is a bit much…unless you have a really really slow connection…
I founded why it was so long but I didn’t solve it.
In fact, I use a stored calculation on a table. When two clients connect to same form (link to this table) who display this calculation, the blue exclamation mark appears.