We do use YTP. I figured it was related, I remember issues when they first released their page builder systems and UIKit 3.
I did test with the default Joomla theme and it worked as expected.
There are errors reporting that the labels <strong>FOR</strong> attribute doesn't match any element <strong>ID</strong> This might prevent the browser from correctly autofilling the form and accessibility tools from working correctly.
To fix this issue, make sure the label's for attribute references the correct id of a form field.
=> <label id="creator-lbl" for="creator" class="hasYsPopover" title="Event Creator" data-content="User who is marked as the event creator"> Event Creator</label>
If I remove the class GSL-Switcher the form is displayed. If i change it to uk-switcher and change the state to active (manually) the form is displayed.
Seems to be an issue with the GSL-Switcher.
There is also an issue with the Category field. The label is displayed (when you can get the page to show), but the dropdown of categories is not displayed, I can see it in the code.
Thanks Geraint