Thanks 6v6gt.
For a start we need to assume its not just 32bits.
Could be a C++ string (dynamic array) at the every least. Or some ESP32/arduino structure we would prefer to know only the high level about.
As for fixing affinity to a specific core, that's still very interesting, are you able to link to an Espressif article please. Although it makes sense as 32bits just sounds like one byte in memory. Not even necessarily a whole word (don't know how ESP32 manages memory). So I don't see how you can have written anything, if you interrupt it. Yeah you can write bits, but I've always assumed that was effected for you by rewriting whole chunks/bytes/words.