(Let's just stipulate for the moment that you're replying in good faith, and not adding fuel to the denialism fire with your "no planes fell from the sky" finish.)
Or perhaps the chips in ATMs and the chips in PCs were different at that time. The system was based on x86 architecture generally, but - unsurprisingly - had a number of specialized components.
@tychotithonus @robertatcara
We were told anything with a computer chip would fail, including household items & planes.
I argued this from 1998. I deliberately didn't modify anything. The only thing that happened was the date changed. My computer was a 386 AT (pre pentium)