OK, so it's actually managing to talk to the
I2, so the problem isn't the cable & the switch is in the right place.
All I can think now is that it could possibly be a firmware problem (i.e. a corrupt module or setting for the vision system).
You could try the following to see if they help:
1) Use Assistant 2 to reset to factory defaults, then retry the calibration process.
2) Try reinstalling/refreshing the current firmware on the
I2 via Assistant 2, reboot the
I2, then retry calibration.
If neither of those work out then if there's a firmware downgrade available, you could try going to the previous version and seeing if you can calibrate. Beyond that I'm not sure there's anything else you can do as an end-user & you might need to talk to your DJI supplier to see if they've any better ideas