The sticky jump bug was caused by some bad logic and there's a temporary DSO fix for it.
I would love a solid repro case for this bug. If you can reproduce it please let me know.
1. Start any map on fullscreen.
2. Play normally.
3. While a button such as mouse2, space, shift, w, a, s, or d, (or any combo thereof) is held down, have the application lose focus (ie an accidental alt-tab, an IM coming in, or a windows-key tap(windows key might have been fixed recently; however it was a problem for me on TGE 1.5 and I know that an alt-tab still works in Legions so I'm assuming this will still, too)).
4. Give the application focus back while the exact states of any button is not the same as it was when the application lost focus.
5. The button states are now reversed.
This may or may not be the cause of the poster's bug, though it can have a very similar effect on them.
This bug has been around since at least TGE 1.4.2; I'm able to reproduce it in a project I did for school some years ago.