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The VIVE Ultimate Trackers may lose their tracking information if the battery runs out or may have trouble connecting to the dongle. Charge them back up, unpair them from the dongle and re-pair them and run VIVE Space Calibrator for the tracker marked with the star.
My Quest headset went to sleep and when I put it back on the tracker position has changed
Any time the headset loses tracking or is taken off your head, the VIVE Space Calibrator play space alignment will drift. Ensure your room is well-lit and that you have set the Meta Quest headset sleep time to Never in the power settings menu of Horizon OS in the headset.
Useful Resources
VIVE Ultimate Tracker PCVR Beta Troubleshooting FAQ (Discord link)
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