I have a person who is matched and RM says there is something new for her so I go to look.
I click on the Sources tab which says (1) on it.
Both the RM Sources and the FS Sources say "Loading...." and it has been that way for 10 minutes.
I've seen this before. The screen is not frozen, I can go back to Share data tab.
But when I come back to Sources (1) it is still saying that it's loading.
The only way I've found to get out of it is to Close the window (button at bottom right corner).
If I go back in to the What's New list of people with changes, this person is gone from the list because I tried to work on her.