It's highly unlikely that the firmware update caused the issue. Thousands of others have had no problem.
You said that the controller set a home point after the update. That would have required a good GPS position lock. Are you still having the...
As tempting as it might be to accept delivery, it is the right thing to do to refuse it, and DJI are not bad guys, so deserve to be treated fairly by us, as they would treat us in warranty situations, which is mostly very good. Best of both...
One thing I am more uncertain about is whether the batteries will discharge if they are in their dock and that dock is plugged in. Mine has been in that state for more than 24 hrs and my packs are still 100%.