(1.19.4) double Fluid in BlockEntity not working correctly

[ElTotisPro50]

Hi, im making a BlockEntity that can contain fluids, and render them in the GUI, only one fluid works perfectly, I can fill or drain it, sync it to the client, and render it. The problem comes when i try to have two fluids in the same GUI, depending on what I delete or leave, the fluids act differently; for example, deleting both of them from "saveAdditional" and "load" methods makes that the fluids cannot render. Also, it can only render one fluid alone, or again, render one fluid, but twice (copies one fluid to the other one). FYI the left one is water, the right one is a red custom fluid. How can I fix this?

BoilerBlockEntity: https://pastebin.com/e6b2U3sD

BoilerMenu: https://pastebin.com/D375yCNr

BoilerScreen: https://pastebin.com/WMrK83Du