There's an issue with it draining which is why I started poking around.
So I guess the flush is ok but I figured I'd try and soup it up if I could while I was looking. I'm going to run some cleaner and descaler or something through it at some point. Need to find dunny specific stuff.
Does this look like the cistern water level is too low? Should it be at the (what I think is a) 6L line?
How would I adjust this so it fills fully?