Hello,
Do you use 1.0.1 version of AMP plugin?
Check settings of the plugin and read our docs – https://xstore.helpscoutdocs.com/article/114-appearance-section https://xstore.helpscoutdocs.com/article/118-custom-css-section
Have you created translation for the AMP plugin? Try to Sync it. Provide temporary wp-admin access, so we can take a closer look.
Regards