HI
You website is working according to the theme design layout. System uses an appropriate image depending on the situation. For example, there is no need to load full image 2048×1365 for the product gallery or for the shop page grid because it will slow down the site, and system loads the shop thumbnail size from the WooCommerce settings, or there is no need to load full image size of the post for the post widget and system uses WP thumbnail size etc.
Sp we will recommend you Please choose 100X100 size and upload more categories image and then check your website category if you sill facing issues with image size let us know we will change it by change in css rule.