Pressing Ctrl will scroll an opened document to top. That affect only unfocused pages.
How to reproduce:

• open some long document (in my case it was a big C++ file)
• scroll to some position in the document (without clicking on the document)
• press Ctrl
• the editor will scroll the document to the top

Actually this is very annoying during work, when you have found some place in the code and want to do something, accidentally press Ctrl and the document unexpected scrolls to top.