Fuzzy Thumbnails, Thumbnails Wrong Size

I know this topic has been discussed many many times, and I’ve read many of the posts. I still can’t fix the fuzzy thumbnail issue. Here’s the problem and my attempts to fix:

I’m starting to use Woocommerce with Avada, 7.1.2 and put up a few products for testing.

The thumbnails are fuzzy and the wrong size (100×100. I followed the instructions to adjust the thumbnail size in Appearance > Customize > Woocommerce.

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Main image width: 750
I set the thumbnail size to 375:
750 divided by 4 x 2 (retina display)

The “uncropped” radio box is checked but the thumbnails are showing at 100×100 instead.
Avada’s WooCommerce Product Gallery Slider is ON.

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I downloaded the Regenerate Thumbnails plugin and ran it. Results:
woocommerce_thumbnail: 375×0 pixels (proportionally resized to fit inside dimensions)
woocommerce_single: 750×0 pixels (proportionally resized to fit inside dimensions)
woocommerce_gallery_thumbnail: 100×100 pixels (cropped to fit)
shop_catalog: 375×0 pixels (proportionally resized to fit inside dimensions)
shop_single: 750×0 pixels (proportionally resized to fit inside dimensions)
shop_thumbnail: 100×100 pixels (cropped to fit)

I cleared all caches: Browser, WP-Rocket, Avada Fusion Cache.

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Checked again in Safari, Chrome and Firefox. No change to the thumbnail size or the fuzzy images in Safari or Chrome.

The thumbnails don’t even appear in Firefox. They are there in the inspector but the thumbnails aren’t “pushing” the tabs downward to reveal the thumbnail images.

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Any help in resolving this will be appreciated.

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