Hey Lemmino,
Is your door a Physics Actor? In MyCharacter Blueprint Components, check Collision on [ROOT] Capsule Component. Capsule Component is what is used to detect collision with world in general, rather than Mesh. Expand Collision Presets section. If you are using Pawn Collision Preset, which MyCharacter Blueprint uses by default, then Collision Enabled will be set to No Physics Collision. Switch Presets to Custom, and then switch Collision Enabled to Collision Enabled.
Hope that solves your issue. Please let me know if it does not and we’ll look into how you’re moving your door.