review photo is not clear

I’m having a big issue with the review image quality across my entire site.

The images in the review section look super grainy and blurry. It’s the same on the homepage, the product pages, and even when I click the image to see the enlarged version. It’s like they are being over-compressed or resized too small.

Since the photo reviews are crucial for my sales, I need them to look sharp and clear.

Could you tell me how to stop the theme (or plugin) from lowering the quality? Is there a setting to show the original resolution or at least a much higher quality version?

Please let me know how to fix this. Thanks!