I somehow accidently unlocked the display on the top left in the PCB routing view (which shows the active layer, snap grid etc.) and now it follows the y-axis of my cursor, is it possible to fix it to the top left again?
Move your mouse so that the window is where you want it to be fixed and press Shift+G.
If you let your mouse rest in the editing window a while the information window will expand to show you some shortcuts associated with it.
You're lucky you're not using Cadence. I once undocked the command window and found out it can never be re-docked without an re-install. A known bug for years apparently.