My answer assumes that you are using FileMaker 12 or later.
Enter layout mode.
Try moving the portal a few pixels. Does Name field move with the portal? I predict that other fields in the portal row move but that the Name field does not. This shows that the name field is not "owned" by the portal as it should be.
Here's how to fix it:
While in layout mode, drag the name field completely away from the portal and release your mouse button. Then drag the field back and carefully position it in the portal row so that it is fully enclosed by the portal row boundaries before you release the mouse button. (It doesn't have to be exactly where you want it as long as it is fully inside the portal row.
Test by moving the portal a few pixels to confirm that the field now moves when you move the portal.
If needed, you can now use the arrow keys or the alignment tools in the inspector to fine tune the final position of the field inside your portal row.
(The most common source of this issue is to use the alignment tools to pull a layout object from outside of a portal into the portal row. This puts the object where you want it, but it does not become part of the portal as you need it to be here.)
Filemaker 7, actually, but your instructions worked. Thank you very much!
The difference in this for older versions is that the field will not move when you move the portal in older versions even when it is placed correctly.