The Bug:

The structure block UI selection outline doesn't highlight the right side of certain focused fields.

This only seems to affect fields that have another field to the right of them.

Steps to Reproduce:

1. Place down a structure block and open it.
2. Select one of the affected fields. See affected_fields.png
3. Look closely at the right side of the selection outline.
4. Take note as to whether or not the structure block UI selection outline highlights the right side of certain focused fields.

Observed Behavior:

The right side of certain focused fields isn't highlighted.

Expected Behavior:

The right side of all focused fields would be highlighted.