It has to be browser cache if anything.
Please try to clear it / try with different browser.
I had no problems with any forms in your CMS.
You’re using heavily modified theme, possible modified source code, but it was working just fine for me, campaigns, layouts, schedule everything without problems.
The one item that I’d like to mention is, I noticed you’ve changed the link to Source Code / GitHub, just as a reminder you can do that, but if you do then you need to provide the source code / offer of the source by alternative means it’s one of the requirements of AGPLv3 - Open Source Xibo
I’m sure you’re already doing that, just thought I will mention it.