Safari is unable to open Microsoft Outlook pages

Safari is refusing to open Microsoft/Outlook pages multiple times a day: either the page seems to open normally but then does nothing else (see screenshot) or it fails to connect entirely, returning a variety of error messages. Yes, clearing the cache tends to fix it, but breaking my workflow to clear cookies several times a day isn't an option.

Apple clearly hasn't felt it necessary to address this in the 2+ years that people have been posting about it, but I figure it can't hurt.

[Re-Titled by Moderator]