Two years ago, I've had Factorio crash once on a null pointer exception. I reported the crash to the devs and, likely because the crash place had a null check, they told me my memory was bad. Same as you I said "wait no, no other software ever crashed weirdly on this machine!", but they were adamant.

Lo and behold, I indeed had one of my four ram sticks with a few bad addresses. Not much, something like 10-15 addresses tops. You need bad luck to hit one of those addresses when the total memory is 64GB. It's likely the null pointer check got flipped.

Browsers are good candidates to find bad memory: they eat a lot of ram, they scatter data around, they have a large chunk, and have JITs where a lot of machine code gets loaded left and right.