Hi Sonya,
My recommendations:
1. Even if you can't upgrade right now, plan doing it at some point in the near future. I know this isn't what you want to hear right now ;), but using new versions you'll benefit from new features, performance improvements, fixes, etc. Unless you're dealing with a totally legacy application, it's really worth upgrading.
2. Did you try putting <xhtml:meta http-equiv="X-UA-Compatible" content="IE=10"/>? (Since the problem is just with IE11, you can use IE10 instead of IE9 in this setting.) I am not sure how your app works, but the best place to put that is most likely in the theme, e.g. theme-plain.xsl.
https://github.com/orbeon/orbeon-forms/blob/tag-release-3.9.0-ce/src/resources/config/theme-plain.xsl3. If you're already done changes to Orbeon Forms, you could put the patch for IE11 on the version you're using, since this is a pretty simple patch:
https://github.com/orbeon/orbeon-forms/commit/0d156deb92d57ec4714e24afe04438875683ce49You'll let us know how it works,
Alex
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