If you set both the top and bottom resize anchors for a portal it will increase in number of rows as the height of the window is increased. I use this method in some FIleMaker Go layouts to help the display adjust for a change in device orientation.
There actually is no empty row and what you see has nothing to do with the fact that these are grand child records. This is the "add row" that appears in a portal automatically when you enable "allow creation of records via this relationship". If you disable that option, this "add row" no longer appears in the portal. At the same time, you lose the ability to add new records in the portal by entering data into a field located in the add row and would need to use a script to add a new record to the portal's table.
Thanks for the quick response Phil. I have been setting the top and bottom resize anchors on the portal. The portals do get "larger" but they do not add any rows. The rows just also get bigger. I am finding the what I am calling the resize anchors in the Edit layout mode, in the inspector in the position tab under the autio-resizing label then checking the padlock icons for the top and bottom. Are these the corrector anchors? I have attached an image of how the portal changes when I do the steps above then resize the window in browse mode.
Your explanation about the row not actually being really there makes sense, and it explains why I couldn't filter it out. It also makes sense that you would have to disable the allow creation of records via this relationship option to make it not show up. If you turn it off it also turns it off for the parent as well as the grandparent which is not what I want but your comment got me thinking so I duplicated the table as a different instance and created the exact same relationship but turned off the "allow creation of records via this relationship" and then pointed the portal to this new table instance. And that totally worked.
If you turn it off it also turns it off for the parent as well as the grandparent
It does not do that. Perhaps you disabled this for the child table instead of the grandchild in the child to grand child part of the relationship chain?
In your portal, return to layout mode (edit layout) and select the fields in the portal without selecting the portal. You can hold down the shift key while clicking them to do this. Then use the inspector to set the fields anchors back to "top, left". Then select just the portal (click the area below the fields) and make sure that top and bottom anchors are selected.
In the uploaded image, the two portals shown both have 7 specified as the number of rows in portal setup. The left hand portal has top, bottom selected for just the portal. The right hand copy has top, bottom selected for both the portal and the fields inside the portal row.
Brillant. So it was the auto sizing inside the document changing it. Thank you for your insite.