Seems like this mod does not override the stack size for stacked items added by some compatibility mods. I'm assuming that adding them as optional dependencies would fix the issue. You may also want to look at adding optional dependencies for other compatibility mods, these are just the ones I'm currently using.

https://mods.factorio.com/mod/Deadlock-SE-bridge
https://mods.factorio.com/mod/DeadlockStackingForKrastorio2

Those mods shouldn't be using data-final-fixes.lua! Since they already have Krastorio2 in their dependency their data.lua is always called after K2, which itself doesn't do anything significant in the final fixes.

I can add them but it's definitely a mistake on their part.
And i can't believe the mod renaming didn't counter this problem... Maybe sorting happens on the mod name, not filename. Not gonna change it though.

Thanks for the quick fix! It's working perfectly now.