OE Reasons table has illegible data

I am debugging an issue with Sales orders . We maintain versions of Sales orders that can be updated manually or using file uploads. The file upload is a csv file that can update Schedule Ship Date and notes. We do not pass any value for the version reason_code.

There are multiple lines in the oe_reasons table with a empty but not null char for reason_code. When i select length , it returns 1 but there is no value. However it is being selected in a query that compares not null.

Has anyone faced this ? I am trying to understand how the reason code is being populated with this character. its not null, trim doesnt work so its not a space.