Creating an action that uses text will change the language from US to UK

I like to watermark my images in the lower left or right corner. I've automated this with actions.
When doing do, the language changes from English:US to English:UK 

My action is assigned to F4 or F5 (lower left or lower right)
Type tool - Website name
Move to the bottom corner
Apply a style.

That's all. However, the language changes in the character tab. It's not a big deal, but it's a pain to keep switching my dictionary back, as my personal additions are in the US dictionary.

My Adobe Cloud is set to English:US, and winding back to previous versions doesn't resolve the issue, so Photoshop might not be the cause; it's just the only app affected.

I'm stumped.

***Edit—My workaround is to add changing the language back to English as part of the action steps. So it's fixed for me, but this is still a strange occurrence.