I cut and paste from acrobat files all day long. Suddenly the arrow keys are acting weird.
I click on the document, hold my shift key down, and right arrow and instead of selecting character by character, (or with control, selecting word-by-word) my cursor jumps a full screen down. I cannot select words, can't press shift+end to capture a whole line. The only way it works to select text is to remove my fingers from the keyboard and click with the mouse which is SO SLOW!
As explanation given above, we have tested the same at our end and this issue is not reproducible.
Using the Shift+Right Arrow/End key able to select the text. Using the Shift+Down Arrow definitely it would go to the end of the page quickly.
Was it working fine earlier for you? Or did you make any changes before it started acting this way?
This is't a bug with the application, so what we can suggest is to check with other document or reboot your computer once.
Also check if there is any pending update of the application. Open Acrobat>Edit>Help>Check for update