I did find the cause of my issue; there is a new "Keyboard shortcut override Toggle" that is next to the Snaps Toggle that was accidentally clicked, causing all the mess.
Thanks anyway.

Been trying out 3DSM9 for a few days now, already familliar with some of the other versions but the UI always finds a way to mock me. In a perspective view, I am attempting to navigate using walkthrough mode (WASD keys + mouse). While I right was in the middle of a project, conflicts started happeni...