VIVE Steam VR Unresponsive in 4.18 and 4.17

Starting yesterday (2/23/2018) whenever I launch UE4, the SteamVR window displays “(unresponsive) UE4Editor.exe”

In UE 4.18.3, If I try to run my level in VR Preview, the HMD and motion controllers appear to work as expected in the mirrored monitor display, but the HMD only displays a default SteamVR loading environment with UE logo and loading animation.

Sometimes, while in VR Preview, if I wait a random amount of time, the HMD will start to work and the SteamVR window “unresponsive” message will disappear. However, once I exit VR Preview and try it again, UE4 falls back into the “unresponsive” state.

This also occurs in a blank project in 4.17.

If I run a packaged project from 4.18.3, the HMD works as expected every time.

The HMD works as expected in Unity and all SteamVR apps I have tried so far.

It doesn’t matter if I try console commands like “vr.bEnableStereo True” etc.

Specs:
Windows 10 (version 1709)
GeForce 970 (84.4.84.0.2c)
SteamVR 2018-02-09
HTC VIVE Pre

I’ve noticed the unresponsiveness a lot as well with the steamvr window and unreal engine.

Basically unreal engine is not ready for vr.