Nothing Can Swim in Custom Fluid, Not Even Player

I'm currently developing a mod centered around a new dimension full of abandoned factories and nuclear waste. My first order of business was to make a potion effect called "Dissolution" that could damage armor, which ultimately was successful. Then, I attempted to make a custom fluid called "Solvent" that acted as the equivalent to the Nether's lava lakes. I managed to add a procedure that gave Dissolution upon contact with Solvent, but when testing noticed a major problem: Solvent has no water physics or collision (the procedure works though). I tried removing the procedure, but that didn't work. I created another fluid that had no procedures attached, but that also had no physics, so it seems to be a problem with more than just Solvent. I learned that setting the template to WATER would enable swimming, but it was already set to that template, so I reverted the stats to completely match water, and it still didn't work. I then tried to attach Solvent to the vanilla "water" tag based on a forum post, then when that failed I tried the NeoForge "water" tag, which also failed. I'm currently on the most recent version of MCreator, have verified that procedures from other blocks/items don't interfere, and use a relatively high-end gaming laptop. I have no idea what's going on here, and I'm worried that it's impossible to make a functioning fluid block for my mod.