Symptoms

Cannot change SmartObject property type for a SQL SmartObject properties.
 

Diagnoses

This is known issue when you are unable to change the smart object property type post SmartObject deployment. GUI seemingly allows you to perform this change but it will not be saved.
Sample reproduction steps:
1. Create a SmartObject with properties ID and Action, with Number and Text types respectively.
2. Deploy the SmartObject.
3. Try to update the SmartObject property type from Number to Text. You are allowed to make this change in GUI, but once you click OK in respective dialog property type reverts to one which was initially set before deployment.
 

Resolution

This is known issue logged internally with workaround available. Workaround is to open the SODX file as an XML file and change property type in the XML itself.