[1.16.5] startOpen() in LockableLootTileEntity not called

So, I've been working on adding a few kitchen blocks, and just completed adding all 16 different variants of the counter. I have a model + textures for both the closed and open blockstates, but the startOpen function that handles the change in texture and tick scheduling isn't being called. From reading both the barrel block and tileentity classes, there's no reason it shouldn't be called, does anyone have any idea on what the issue might be?