Note that the Internet Explorer 11 browser was released in 2013. The version of the controls you are using was released two years before that. Thus, it is possible to observe unexpected behavior when opening the page in IE11.
If you would like to support modern browsers it is recommended to update the controls to the latest version. The current release is 2016.1.113. Give the latest release a try and see how it works for you.
If you would like more detailed information on upgrading the controls please check out the following article.
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