I started this post because today my pages were not displaying properly on Firefox. I have now found this to be an issue with Adblock Plus, probably due to an update. I expect it will be resolved soon.
For information, this was the issue:
The section of the listing: 'Item description', 'Item Specifics', 'Item description from seller' 'About This Item', not showing. These parts of the page were blank. They appeared after disabling the Adblock and reloading.
Adblock Plus is an excellent ad blocker and normally works well for me.
12 July 2025