Hi, DIYer. I replaced a leaking angle valve a few months ago. Over the past few weeks, occasionally I would hear the water filling in the tank when not in use. I've been meaning to look into it, but a new problem has developed. Twice in the past few days, the toilet would not fill after flushing. No water running at all. I turned the angle value off and on, with no change. But then a few minutes later the toilet would suddenly start filling again and operate normally. Any idea what this could be? Thanks