MCreator Client and Official Client differ in results

I am working with the first 1.18.2 snapshot available as of now. To summarize what's going on: 

- I have a PLAYER LIFETIME integer global variable assigned to the player. Let's call this Alpha.
- I have a PLAYER PERSISTENT integer global variable assigned to the player as the "max" value Alpha can reach. Let's call this Beta.
- I have a system in which Alpha constantly increases until it hits the value that is Beta.

So what's the problem? Well, in the MCreator test client, the system works perfectly as intended - it regenerates nicely and adjusts according to several other factors in the background. However, when I export the mod and use it with my premium Minecraft account and launch the exact Forge version my mod requires, things go way out of pocket. Alpha won't regenerate properly at all, and everything I made glitches out in very weird ways. I thought "maybe pressing the 'regenerate and build code' button might fix it" but honestly I think it just made it worse. (It even crashed a few times beforehand claiming that my mod's "Particle Pack" or something didn't exist, but randomly fixed itself after a few runs.)

I'm aware that this is a snapshot so a LOT of bugs are to be found most of the time, but this seems a bit odd in every way. Wouldn't the bugs also apply in the normal client (no the MCreator one)? Why are they different?

Thank you for your time.