I used to be able to press the arrow keys (or shift+arrow keys) to move any type of layer whilst I was keyframing, but now all it does is move the video forward one frame, meaning I have to move objects around with my mouse which is combursome and infuriating at times as my work require a lot of very precise movements. Does anyone have a solution to fix this?
Editing, Effects and Titles, Error or problem, User interface or workspaces
You really do need to supply more info, like your workflow. From which panel are you editing from, like Essential Graphics, etc.
When you have the program monitor selected like you've just highlighted a graphic, you can use CTRL-left/righ/up/down to move the graphic. Add SHIFT to that and it moves in the big nudge you have set in preferences. Also, search for "Nudge" in the keyboard shortcuts dialog and you can find the ones that nudge in the program monitor, etc...