I've just encountered an odd issue.
I've had this form for a long time and a strange thing happened this morning.
I have several WYSIWYG fields in the form and all are fine, except the first one in a subgroup. For some reason, the first WYSIWYG field in a subgroup displays as a text rather than a WYSIWYG. All WYSIWYG fields after it (in the same subgroup) are fine, just the first one is wrong.
The first WYSIWYG field is displayed conditionally and is cloneable, as are all the fields in the subgroup. If I add a second WYSIWYG field and remove the first, it stays a WYSIWYG field until I save the form, then it's a textarea field again.
This issue wasn't present yesterday or at any time previously, it just started this morning and I haven't made any changes to the form.