SOLUTION:
It seems adobe removed GraphQL tab while creating the content fragment model.
The new way of defining API name , query field multiple, query field single values is
If your model name is Test Model then ,
- If you want to execute query field multiple then you have to append your model jcr:title to the List i.e.., testModelList. By using this testModelList you can query multiple.
- If you want to execute query field single then you have to append your model jcr:title to the ByPath i.e.., testModelByPath. By using this testModelByPath you can query single path.
Note: If you install sp17 then you should update the existing persistent queries to match above naming conventions.
Example to change old queries for new SP17 for model named Test Model:
If earlier multi filed name is : testList
Then new multi filed name is : testModelList
If earlier single filed name is : testByPath
Then New single filed name is : testModelByPath
Adobe mentioned this as known issue :

https://experienceleague.adobe.com/docs/experience-manager-65/release-notes/release-notes.html?lang=en
Thanks!!