The zero value in Default Answer field disappears, after you finish editing the survey item.
Reproducing the Issue
- Go to the Survey work centre.
- Select the Survey work centre view.
- Search and open survey 123 (123 represents the ID of the survey).
- Select the Design facet.
- Click on the Amount hyperlink within the Items table.
- Enter 0 (zero) in the Default Answer field.
- Click the OK button.
- You can see that the zero value you entered has vanished.
This is the standard expected system behaviour.
The zero value for Amount type of fields is considered as blank.
KBA , SRD-CC-FED , Feeds , How To