There is no universe in which a LightBurn update changed the steps on someone’s 4th axis.
A point of confusion I have seen relatively often, and coded in a warning for, is people using “Import” for LightBurn project files instead of “Open”. “Import” is used to bring vectors from a file into an existing project, without cut settings, where Open is used to open an existing file, including the settings. If you run LightBurn, and use “Import” to bring in a project file, it wouldn’t bring in the cut settings with that file, and would just leave the cut settings as whatever they were from the last thing you worked on.
The only other explanation I can think of is if you pointed the mouse at the pass count and used the scroll wheel accidentally - that could change the number. I’ve tried to find a way to lock those controls so you have to click them first to use the mouse wheel, but haven’t found a way to do that yet.