Thumbs not showing after Joomla update

Hi
I just updated https://madsensgalleri.dk
I migrated from J3 to J4 and updated to php8 aswell
None of the gallery thumbs are visible in front end. F.inst. this page you can hoover over "invisible" thumbs and see large img in lightbox
https://madsensgalleri.dk/malerier

What's the fix here guys?

Replies are visible only to logged in members with an active subscription.