Zend certified PHP/Magento developer

Empty shopping cart button not working

I’m not sure what I have done to mess up the empty cart button in the shopping-cart page. Nothing happens, not even a page-refresh.

Its a multishop and it dosnt work on any shop. Not even using default luma shop.

I got it to work once in chrome Inkognito mode just before. It pupped the warning popup and cleared the cart fine. Afterwords it didnt work in Inkognito mode even.

What to look for or how to debug this?