>>1485844Some of them, notoriously: the Fluidmaster series, just aren't designed that way.
Some potentially stupid questions to get out of the way:
>Have you tried lifting the arm manually? Is water still flowing, albeit more slowly?If water still flows when the valve is manually closed, the thing needs to be replaced. No way around it.
>Is this a recent problem or has it been this way since the valve was installed?If it's recent, what changed? If it's not, you might be able to nigger-rig a "fix" by either attaching a longer hook or raising the height of the overflow tube. Get creative.
Or you can just replace the valve.
