Smart-a$$ answer is to find an old 3 gallon pot in a salvage place. Best answer is to fiddle with the chain that goes from the handle to the flush flapper and see if adjusting its length makes a difference. If it's too short it might result in letting the flapper closing too soon and allowing your deposit to remain.
There's something blocking it sometimes if you turn the water off in your home and turn it back on sometimes calcium from the pipes break loose and cause blockage in new style washerless valve assemblies.
Check the flapper and seat. Ensure that the flapper chain is not tight or caught underneath flapper. Check floor underneath tank for any sighs of water leaking or seeping from tank. tight tank to bowl nuts. good luck