My G3X loaded with firmware 8.81 appears to have some logging issues. Although logging was enabled in G3X configuration no data log was recorded for a flight that included some performance test points.

I verified that no data log was recorded for several system re-boots. I then disabled logging and re-booted followed by enabling logging and another boot. Log was then recorded for hangar test and for the next flight.

Garmin has been notified but has not responded. Don't assume you are logging data just because an SD card is inserted and logging is enabled. If you see that a log was not recorded please tell Garmin. They may respond to multiple reports even if they'd rather ignore just one.