Sorry, i forgot the link to my site.
Here we go: https://www.inno-duppen.no/
An you can see the issue if you go to a single product and then select a category in the upper left category widget. Then check the source code.
https://www.inno-duppen.no/produkt/inno-duppen/bombarda/inno-bombarda-intermediate/
I found it yesterday in all my 4 sites when i saw some wierd padding issue after clicking on category in single product. Sidebar and content was very tight together.
Just checked 2 of my sites with all cache emptied, all plugins deactivated and issue is the same. When checking source code the body class contains all classes from previous single product.
Brgds
Rune