Final update!
I don’t know why I didn’t do this a week ago, but I took the bass to a local luthier just to see if he could salvage the pickup by soldering it to the preamp a lot better than I did with the lousy soldering iron I own.
In the process, he figured out the pickup was indeed the problem, but found a way to solve it - he simply opened it up, tested the voltage, re-soldered a point connecting the coil and voila! The pickup is fully functional again and I couldn’t be happier.
It’s a shame the QA at the factory didn’t pick it up (no pun intended) but I guess if it worked okay, that’s good enough.
(I should know, as a software engineer, whatever works in development might not be the same in production…)
This is the happy ending to this story, and fortunately I can just play my bass now with no worries, no delays of waiting to shipments and what not. All is well again 
The lesson for me would be to consult a local professional as fast as possible, and if the problem is beyond fixing, go to the source and contact the manufacturer.
Thanks everyone for tuning in!