It looks like your JSON contains some empty strings. If they are always empty, cleaning up the JSON would help. If they are dynamic, you sometimes have to push through the errors.
@Chris_Skiles good point and I double checked. I have 5 rows returned by the query and all fields are populated... I wonder if this is a bug... Perhaps the json field name companyid makes retool think there are duplicates? Not sure...
happy to see you found a solution!! feel free to mark @Chris_Skiles's post as the solution so other searching can easily find this... if you don't mind and have the time that is