Redshift View throws "UNION data types mismatch error" when it is datashared but otherwise it works fine

We have a view in redshift which does UNION and it does not complain about data type mismatch but when we do a datashare of the view to another cluster and try to do a select , it gives UNION mismatch error. Why is it that the view can handle the data type conversion on it's own but throws error when it is datashared?