解決済み
このトピックへの返信は締め切られました。
Set that field as required and then use this script as 'Validation' of that same field:
event.target.required = event.value == "Please Select Option" ? true : false;
A submit will be blocked when a field is both required and set to it's default value. So make "Please Select" the default. I don't see any need for the script.
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