Every product page format is weird (not working)

I use WordPress and Woocommerce as my shop plug-in. The theme is a child theme based on Storefront. Everything was running smoothly until recently.

I just noticed that all my pages were alright but the pages for each and every of my products (all of the product pages are defective). The format of the page is weird. It is as though the page format is forced into mobile format even though the page is accessed from a desktop PC. The page width is suddenly very narrow. In addition, the product image does not load AND products cannot be added to the basket. Those two last issues appear also when accessed from a mobile phone.

I do not know if the problem is related to an update or corrupted file. My knowledge is WordPress and Woocommerce is anything but good. Apps and plug-ins are provided from the website host.

I would appreciate any educated guidance. Thanks.

The page I need help with: [log in to see the link]