OK, first of all, this doesn't only have problems in IE 11 or Edge. It also doesn't work in Chrome < 50 (at least).
1. I removed basically EVERYTHING from the Template source code, other than the form code. So there is no longer ANY custom code.
You're loading 6 additional remote JS files from within a Rich Text area:
https://code.jquery.com/jquery-3.3.1.min.js https://go.spirent.com/rs/627-MTZ-252/images/fontASM.js https://go.spirent.com/rs/627-MTZ-252/images/date.format.js https://go.spirent.com/rs/627-MTZ-252/images/chkDate.js?v=6 https://go.spirent.com/rs/627-MTZ-252/images/captchaTest.js?v=5 https://go.spirent.com/rs/627-MTZ-252/images/passKey.js?v=2
Look closely at the second one, that's where at least one of your bugs originates.