Blurred zoomed-in product photos

I've ran into a weird rendering problem:

My  photos have a zoom factor of 2.5 on hover.

Every time I zoom in the image looks horribly blurred out and pixelated. Nothing seems to do the trick unless I manually zoom in the entire site (  ctrl + mouse roll ) to a point where the photo is no longer visible on screen (  > 250%  zoom ) and then reset the page zoom back to 100%. Then suddenly the zoomed in photo appears crisp and looks they way it should.  

Image size is only 433Kb so I'm really running out of ideas as to what might be the culprit 

I've tried with 3 different PCs on 2 different browsers in 6k x 4k as well as 60% and 40% of those resolutions. Tried in Jpeg and .png with 2 different photos. Same thing happens every single time. Page zoom fixes it instantly and without it photos remain blurry.

Hi. Try contacting Squarespace Customer Care.

I'll do that, Thanks!