Whenever I receive a private message from anyone, the text doesn't wrap and I can only read however much fits in the window until they hit the Enter key. Running Windows 7 and viewing in Internet Explorer 11.
Internet Exploder is no longer supported by pretty much anyone that keeps their websites up-to-date. That's not to say they won't work -- it just means they won't work as well as they might in a better browser. As time goes on, you would start to notice more things breaking because of that lack of support. On your side of things, it's actually more of a security issue, which is one of the key reasons even Microsoft themselves have mostly abandoned it. Microsoft will continue to patch IE11 via Windows updates, but you can bet it won't receive much more support than the bare minimum. It's basically on life support. They want you to use Edge.
I did test this issue in IE11 on my machine, and sure enough, I was able to replicate that behavior. But when I use Edge, Chrome, or Firefox, there are no issues. There's not really much I can say except suggest that you use a more modern browser. Sorry. 🙁