Meredith - check out the suggestions here - Re: Tableau Public viewed on Internet Explorer 11 - Has something changed?
in addition, you might try disabling client side rendering - About Client-Side Rendering to see if that resolves the issue for the short term.
You might also put in a support case although if you are updating Tableau Server anytime soon, I would do that first and then check on the results of that change before filing a case. If the issue persists to a newer version, then this might be helpful to share.
I hope this helps.