Chrome Version: 67.0.3376.0 Canary
OS: Android 8.1.0 on Pixel 2

This may not be related to VR but I see it a lot while testing.

What steps will reproduce the problem?
Not 100% repro steps but generally playing enough results in the Over Scroll refresh ability become disabled.

(1) Open Permissions.site
(2) Enable Camera/Microphone to get permission indicators
(3) Reposition/Resize
(4) Attempt to refresh via "Over scroll", use the touchpad to scroll current page to the top and then further to cause the Refresh to trigger.
(5) Keep playing until it fails.

What is the expected result?
Refresh should continue to work.

What happens instead?
Refresh stops working.  I have been unable to repro outside VR.