I can confirm that JP512 worked.
Conclusion: JP6 does not work on hardware that was previously used with JP5.12 (and I assume earlier), at least not without more than changing the SD card image.
I can confirm that JP512 worked.
Conclusion: JP6 does not work on hardware that was previously used with JP5.12 (and I assume earlier), at least not without more than changing the SD card image.