Issue with writing back to intersection in FCCS with smartview

Summary:

We have a user in FCC with access to all secured intersections but still cannot write back through Addhoc.
Only when the user get access to a form security group they are able to see writable data. (Yellow cells)

The original Addhoc was derived from the form by another user. Even if we create a new Addhoc there is still only read access.
If the form security group is added this will make the user be able to write data.

Content (please ensure you mask any confidential information):

We also checked the Sheet Info but it is clearly stated as add hoc. (So not as form)