I think there’s a bug (or an opportunity to finesse) how the screen refreshes/updates when selecting cells in the spreadsheet using the cursor/arrow keys. Specifically, when selecting cells using the cursor keys and navigating UP or LEFT.
Every other keypress, the screen jumps from the start of the selection box to the end of the selection box. Ie: when you are navigating LEFT and the selection box is wider than the screen width, or when you are navigating UP and the selection box is taller than the screen. It does not do this at all when navigating RIGHT or DOWN, the screen merely moves a few cells at a time, not jumping from start to end.
I have created a small screen recording to demonstrate this behaviour, but I can’t attach it here as I’m a new user, so I’ve uploaded it to Imgur here.
Notice the cell Count in the bottom right hand corner increasing and decreasing as I select further left, then back right to the start.
The generally expected behaviour is that while selecting and navigating left with cursor keys, the screen should stay focussed at the part of the selection that is changing (ie on the left hand edge) and not jump from start to end every other keypress. There may be a slight variation on this while increasing and decreasing the size of the selection box.
OS version: Win10x64
App version: 8.1 (x64)
Downloaded from: ONLYOFFICE website
Fresh install, new spreadsheet, just filled with some dummy data to make it visually more obvious, but the same issue occurs in a blank spreadsheet also.