Thumbnail Ratio

Hi,
We are having issues with our the majority of our thumbnails.
1/ Since changing theme to DIVI, they are nearly all blurry, but only on desktops it seems.??
2/ Thumbnail Ratio is set at 600:200 at present.
We’d like them to be smaller though (to fit more products on the same row, i.e 6 instead of 4). However, the minute we change the ratio to 300:100 for example, the images get awful & even more blurry (regardless of the thumbnail regeneration plugin we use).
3/ Our previous theme made all of those product thumbnails containers look the same (height x width), however they now seem to be related to the thumbnail itself, thus lacking consistency.

I hope you can help!
Thanks in advance,
Loic

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