[oezi]

From a discussion on Garmin nav accuracy:

> Russia (GLONASS) may intentionally give wrong results in your area. Try switching to just GPS, or GPS & Galileo.

https://www.reddit.com/r/Garmin/comments/vo9w0l/comment/ied5...

[Godel_unicode]

If you read down in that thread it turns out it was nothing so mysterious; the ephemeris file for Sony gps chips was expired and had to be updated.