I just found this out.
When you attempt to use the caption parameter while also using gallery code with two images, the caption will not show.
{{infobox character
| title = Testing1
| image = <gallery>
A.baa-Beautiful-white-forest.jpg|image one
Tree.png|image two</gallery>
| imagecaption = The caption will not show with two images.
}}
{{infobox character
| title = Testing2
| image = A.baa-Beautiful-white-forest.jpg|image one
| imagecaption = The caption will show with one image.
}}