When I defined my sort and filter parameters to hide threads that I have already read, I chose Apply and Save. But the change doesn't appear to have been saved.
After defining the filter, I accessed a thread in the Aircraft forum, went to the latest post, then navigated back to the forum via the breadcrumb trail. I noticed that the thread I had just read still displayed, so I opened the Sorting & Filtering parameters again, and noticed that it still showed the original default of Show All. I tested setting it again to hide threads I'd read and chose to apply and save, then navigated into a thread and back. The forum still showed all threads, and when I opened the sort/filter parameter again, it was reset to the default.