When in EDIT mode (screen) I select nodes and I am sure I used to be able to move them either by dragging them with mouse's LMB held down, or I would move them with the ARROW keys.
Suddenly - which is confusing me - when I press the ARROW keys, the whole screen moves.
I just went to another machine and tried it.
That is what happens.
So the machine on which I am working seems to have decided to change how it interoperates what it does with the ARROW keys being pressed.
So something is not on the same page between the two machines.
It only just started happening recently. (Today/this session.)
Because before it was working fine.
I was editing stuff and wanting to move nodes by block sized steps and pressed the SHIFT ARROW keys while having the nodes selected and.... the whole screen starts scrolling.
It will depend what element on the page has focus when you press the keys. If the main workspace (the canvas your flows are on) has the focus, then the nodes will move. If anything has focus then the browser's own handling for those keys will apply.