If you are facing the font size issue with blockquote like below the screenshot to resolve this problem you need to follow this below steps

You will find this option in the WordPress Dashboard -> Navigate to AMP option panel -> Design -> Global -> Custom CSS -> Enter the below CSS code and then click on the “Save Changes” button.
For example:
blockquote p {
font-size: 16px;
} 
After changing the font size of blockquote

That’s it for this tutorial!
We hope it helped you. If you have any feedback or questions, then please share them in the comments section below.