Behaviour - clearError is not able to clear out setError

Steps to reproduce the problem

1. Add the script below on the Text type custom field

   def field = getFieldById(getFieldChanged())
   
   if(field.getValue() == "" || field.getValue() == " " || field.getValue() == null)
   {
       field.setError("error message")
   }
   else
   {
       field.clearError()
   }
   

1. Go to Edit issue screen and prompt errors because the field is null (which is fine)
   
2. When user key in value on the field and then submit but error message showing again
   

Demo - Screen Recording 2020-06-10 at 12.42.04 PM.mov

Expected Behaviour

The clear error should be able to clear the error message when the IF ELSE condition is met.