I had the same problem briefly but after restarting my workstation it was working ok again. (also check your gpu drivers are up to date)
Could you specify a bit more what you mean by: "when I launch VR in UE4" as I was meaning doing a "Preview in VR" but maybe you are talking about something else? Also mention the UE4 version in case it's connected?
@mobkonI got it working but I had to delete my previous project, the new one has no issues. My guess is something went wrong while creating the project and somehow it got corrupted. Right now I'm just starting and worried because I found no way to find out what happened.Maybe it is worth mentioning, SteamVR starts when I open Unreal Engine and not the Oculus application. I don't know if this confused the engine somehow but now I'm manually opening the Oculus application before Unreal Engine, just in case.