Hello, I too am having the same problem with losing tracking in VR Chat. It works fine in SteamVR Home, but when it loads into a world I will have about a second of control over movement and hand motion until the character goes into a T pose. If I’m holding down a button to move, I seem to have control for a little longer (maybe 2-3 seconds) until the character reverts to the T pose.
While the character is in the T pose, I can bring up my in-game menu and select avatar, once I do that I can control the characters hands and waist, but no feet. Also while in T pose, I am able to see the three white tracking balls of my feet and hips which are accurately tracked in the reflection of the in-game mirrors.
Seems like it might be an issue with VR Chat because I never lost tracking with Driver4VR as I was constantly hitting the System Button to check on my feet and hips trackers.
I will attach my diagnostic logs just in case. I’m using a HTC Vive and the Kinect 360.