The name plates of entities with an empty custom name are now rendered incorrectly

This behavior was introduced in 25w20a.

Steps to reproduce

1. Join a world with commands enabled.

2. Run the following command to summon a mob with an empty custom name.

   /summon minecraft:pig ~ ~ ~ {CustomName:"",CustomNameVisible:true}

3. Look at the mob.

Observed behavior

The name plate is very enlarged, covering up most of the bottom right corner of the screen.

Expected behavior

The name plate would be rendered the same as in versions prior to 25w20a.