Overwriting Text Object in Container

I modified the following phaser 3 example, https://labs.phaser.io/edit.html?src=src\game%20objects\container\text%20and%20sprite%20test.js , using the sandbox, to dynamically update the text in the text object. This seems to work fine and I see no visual artifacts.
(Here’s a fiddle: https://jsfiddle.net/beerye3/8jmsudk6/4/ )

However, when I took that same principle and applied it to my game, I see a visual artifact. I use a webfont to display both the score and number of lives for my player, however, when either is updated, I can tell that the previous value is still being rendered, underneath the new value.
image

I fixed this by adding the backgroundColor property to the config for the text object with a value of ‘#000000’. That matches the background color of the scene.