Problem with Images on Product Page

Hi, I’m not sure if this is a Woocommerce plugin problem or if it is from another plugin.
Our website was setted to show a main image bigger than the other ones, with a row of secondary images down below like on this product:
https://refrivan.com.ar/producto/cocina-a-gas-puerta-visor-4-hornallas-58-cm-corbelli-cf-58/
For some reason, the last few products I’ve been adding have their secondary images with the same size as the main one, creating a long, big size chain of images as in these products:
https://refrivan.com.ar/producto/freidora-electrica-domestica-3-lts-simple/
https://refrivan.com.ar/producto/horno-tango-560-a-lena-embutir-tromen/
https://refrivan.com.ar/producto/cocina-domestica-55cm-puerta-visor-maraldi/
I’m not sure why’s happening this, what changed or what should I modify to get it back as how it was before

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