Panasonic has released an updated firmware that claims to fix some instability issues while recording video at higher frame rates using VFR. The Firmware Version 2.2 Available here aims to reduce or eliminate instances where the camera could stop recording video or in some instances refuse to record in VFR mode. Some users have reported rare incidents of corrupted files, recording stops and some camera lockups that could be related to the VFR function buffer and write to SD card procedure. It will be a matter of testing this new firmware to see if it resolves these issues.
In some instances, it was narrowed down to slow SD cards that could not keep up with the data rates necessary or cards that had internal fragmentation that could cause corruption on clips. Glad to see Panasonic addressing this issue. The camera also adds a new menu item for customizing the function button on the new Leica H-ES200 200mm 2.8 lens to different parameters. Firmware Link!