VR teleport not working - VIVE

Is anyone else having trouble with VR navigation using HTC vive?
I am not able to teleport around a model in VR using the controller - it worked as of a month or so ago. I can see the yellow rings, but not the blue controller line, trackpad height not working either. System works fine using STEAM, but not with sketchfab models. I am using firefox - updated graphics card and browser.