We have an older home with a parallel bar tub drain plug that is internal to the P trap. Similar to that of a Bathroom sink. Lift the lever up, to bring the plug inside the p-trap to position to plug the tub.

Works fine one day, now it wont budge, stuck open.

I have removed the t screws on the lever plate and the linkage in sight appears fine. Inside the P trap not much to see, but there is no blockage.

We only have one tub in the house and this makes kid baths go fast. Plugging the drain with a washcloth to slow it down. Still drains in about 10 minutes.

What now? Am i stuck?