No bug is special (or all of them are
). Some of them are tricky to reproduce.
A bug report requires a test case or, at least, the steps to reproduce it (see
https://github.com/koreader/koreader.../bug_report.md).
Github is probably the best place to talk about bugs. The forum is *ok* as long as you fill the same info (device, program version ...)
So, the steps you'll need to do:
1. Reduce your paragraph to a test case or a number of steps to trigger the bug.
2. Check that you can reproduce the bug against the very last version of the program.
3. Attach a bug report (here or github) with all the info needed, including a debug log and your current settings.
Also, please don't mix bug reporting with guesses about how the program works or how the bug could be fixed. It usually doesn't help to understand the bug. Much better to stick with bug templates.