Sluggish walking, no sprinting and airboat doesn't accelerate properly in Half-Life 2

I just reinstalled Half-Life 2 on this system, movement in the game is sluggish compared to what it was the last time I played it.

Here are the symptoms that i've noticed:

• The sprint doesn't make me go any faster, but it still drains my AUX-power.
• Moving through vents and other cramped areas is almost not possible
  as Gordon is moving about an inch per second.
• The airboat doesn't accelerate properly in water or on land. whenever it's on land it's moving as slow as I did in the cramped areas.
  However, it accelerates properly when I reverse.

Solutions as mentioned in the post below have all been tried out.
Gordon Freeman runs way too slowly!

Here's a list of things I've tried:

• Entering the value "sv_alternateticks 0" into the console.
• Manually unbound the sprint key and rebound it using the console,
  • Tried binding it to other keys and it made no difference.
• Pressed the "Use Defaults"-button in the key bindings menu.
• Changed the steam overlay key binding in a way that shouldn't interfere with any button used in game.
• Alt tabbing.
• Tried toggling V-Sync.
  • Tried limiting FPS to 90 and 60 using the "fps_max" console command.
• Checked if VR settings was still active, which the menues indicated that they were not.

I play this on a Windows 10 Pro 64-bit system, that has tried playing this game in VR before.

How would I go about diagnosing and fixing these issues?