I have spent a long time pondering this problem that was presented here, and I think I have finally gotten an understanding of it.
https://travismaynard.com/writing/caching-particle-materials-in-godot
And in the case of the web version, it's using a compatibility renderer instead of the intended renderer (Forward+), which means that it's subject to the problems occurring in this article.
Credit to the guy who found this article, (Discord Name: Vase)