Serving wrong resolution images

Hi,
I’ve installed the plugin and activated compression using VIPS.
It does seems to work, but when I open my website the image quality is terrible.
When looking at the source code, i see that the <picture> tag does contain several urls with the same photo in different resolutions.
For some reason, my website is displaying a bad resolution of the photo, instead of a proper one.
You can see at the url mentioned:
This is a original image:
https://www.tracer.com.br/wp-content/uploads/2020/08/frente-uai-1184×789.jpg
This is a very decent compression, which is included inside the <picture> tag:
https://www.tracer.com.br/wp-content/webp-express/webp-images/doc-root/wp-content/uploads/2020/08/frente-uai-720×480.jpg.webp

However, instead my website is displaying a upscaled version of this file:
https://www.tracer.com.br/wp-content/webp-express/webp-images/doc-root/wp-content/uploads/2020/08/frente-uai-258×172.jpg.webp
Which of course looks terrible because its a tiny image upscaled.

Any idea how to make the browser display the better resolution instead?
I’m using chrome with the latest updates on windows.
My website is using the paid Uncode theme.

Thanks

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