Weird jumps

Describe the bug
Often when the cursor is clearly somewhere in a document, and I press one of hte arrow keys or pageup/pagedown, the cursor jumps to the beginning of the document. If I do a combination like dd, it even removes the first line of the document in stead of the line of the cursor.
Also, when I use end to jump to the end of the line, it does this, but then if I start typing or editing, it jumps back to where it came from.

To Reproduce
I wish I knew. It just happens randomly and a lot.

Expected behavior
Edit and move from where I see the cursor.

Environment (please complete the following information):

• Extension (VsCodeVim) version:
• VSCode version: 1.25.2
• OS: ubuntu

Additional context
Unfortunately I had to disable the plugin because it becomes unworkable. Which may even mean I have to switch out vscode for something else.

The report names no source file, test, or reliable reproduction; begin by reproducing the cursor jump with VSCodeVim on VSCode 1.25.2 under Ubuntu and narrow down the triggering key sequence. Done means cursor movement and editing remain at the visible cursor location for arrow keys, PageUp/PageDown, End, and dd.