Maybe try using this in the XML :
I copied the code from a model condition when it pulls the field from another model and just updated the fields and models to be correct, so maybe that will carry over into the button conditions even though it isn’t an option on the drop down menu?
Otherwise a UI field might work?
If you create a UI field on the wizard model that is a formula field returning a checkbox, and have the formula be :
IF( {{Start_Date_Text__c}} = {{$Model.ScrollEpisodeNext.data.0.Start_Date_Text__c}}, TRUE, FALSE)
And then set the enable condition to be where that UI field either equals true or doesn’t equal true, depending what the outcome you want.
Otherwise you might have to resort to Javascript instead
