Hello, @Creapar desenvolvimento,
I have checked your site the product images appear 300×300 on the home page and on the shop page I have made a video for you for this please watch it first: https://streamable.com/8b5913
If you are facing an issue with a specific product then please share the product URL with us and if possible please provide a screenshot of your issue for a better reference.
Regards 8Themes Team.