Changing 'Product Thumbnail' size on Single Product page | How to?

Hi, in the url below:

https://www.klas-sylph.co.th/en/shop/amanda-be-leo-slingback/

You see that the Product Thumbnail size (i.e. the gallery image) is quite small. I set the size in Woocommerce display settings at 200x150px, and I already regenerated thumbnail after that. But on this single product page, the gallery thumbnail is somehow set at 118x88px. I don’t know where this dimension come from, but I want to make it 200×150 or at least bigger. Can anyone tell me how to fix this?

Any help would be very much appreciated.

Thanks,

John

https://www.ads-software.com/plugins/woocommerce/