pressing shift... like to capitalize or make a special char like : will cause the cursor to move to the start of the window.
Topic on Help talk:DiscussionTools
Have you tried this while being logged out and in incognito mode of your browser ? Quite often things like this are due to browser extensions or gadgets installed in your wikipedia user account, so if you try with those disabled, you should be able to discover where to start looking
it looks to be some sort of spell check interfering on multiple windows devices and browsers, but I am unable to locate any user script or gadget related to spell check that I am using.
Apparently the google translate gadget is often causing this effect.,
yes, i believe that is the one. ive turned it off. should help