Toilets, Sinks, Showers, Tubs and Disposals - Tank refill shuts off water??

Ok I'm at a loss...

I replaced the valve in my toilet today, and now when the tank refill completes the water knob pops out, shutting off the water for future refills. I tried swapping back to the old valve, but now it does the same thing.

So it's good for one flush/refill, then it turns off the water each time. What did I do and how can I fix it?

There are also a few drops accumulating under the knob, should I assume that I have to replace this hose? Is this the source of the issue?

Ack! Help!

Thanks

EDIT: Setting Notification

Welcome to the forums! I am also at a loss. What knob pops out? Do you have a Flood Safe hose leading to the toilet? What type valve is it that you used as a replacement? Fluidmaster 400A is probably the easiest one to change to.

Hi Chandler -

By "knob" I mean the water shutoff valve. It pops out after each fill cycle shutting off the water to the toilet, forcing me to push it back in to turn the water back on.

The Fluidmaster 400A Fill Valve is the new one that I purchased.

As for a flood safe hose, I'm not entirely sure. It is a mesh hose that has been with the plumbing since it was build (2001).

The knob on the shut off valve should not "pop" out at all. Is is a quarter turn unit or a stop-to-stop unit? You may need to replace the innards of the shut off valve, or the entire valve if possible.