Custom fluid behaves like air (no swimming, drowning, or buoyancy) in MCreator 2026.2

I am currently developing a mod in MCreator 2026.2 and running into a frustrating issue with custom fluids.

When I place or generate my custom fluid in the world, it flows and spreads perfectly fine. However, the game engine behaves as if the fluid isn't actually there. It acts completely like air:

• Players and mobs cannot swim or sprint-swim in custom liquids
• Entities do not float or experience buoyancy; they just fall to the bottom as if the liquid didn't exist
• The drowning mechanic does not trigger when submerged

It seems like the fluid blocks lack any collision or physics properties. Has anyone else encountered this in 2026.2? Do I need to manually register specific fluid/block tags to get vanilla water physics to apply, or is there a specific setting I am missing?