Text Change not working when Asset Optimization enabled

Trying to change the text using Ultimate Branding for the required text message called:
This field is required.

The above is a validation text which appears during MarketPress product checkout, when the fields aren't filled. But only that specific text doesn't seem to translate via Ultimate Branding plugin when minification is enabled.

The Text Change in Ultimate Branding seems to works fine when minification is disabled. Please check the chat transcript for more info.