Product Gallery Images Blank

Hi,
A couple of weeks ago my product gallery images started showing as blank white and I haven’t been able to figure out a fix. It’s happening with single and variable products. No new plugins or other changes, everything is completely up to date.

In the gallery thumbnails, if you click one (or select the relevant variation from the dropdown for variable products) the thumbnail image is highlighted but the main picture is still blank. The size does appear to change though if the gallery picture is longer than the featured image. So it’s there, but not showing.

I’ve tried a few things, changing opacity and margins, but nothing is working. I’ve done the inspect element but can’t see anything obvious (I’m not an expert so maybe missing something there.

Someone help please!

TIA

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