Passing the correct parameter by macro

Currently, I have two projectile functions : water.mcfunction and fire.mcfunction. I'm using a modified version of Cloud Wolf's slowcasting pack, and the version is Java 1.21.8
The pack work when running one of those aforementioned function by themselves, but fail when running both function at once. Depending on how it was setup, you'd either see a water bolt suddenly turning into a fire bolt and vice versa.
I tried messing around with how and where I store data, as well as what I used for macro, but they either do nothing or break the system completely.
How do I fix it and make it work correctly?