About a week ago, the toilet started bubbling. Air bubbles were coming up through the bowl. A couple of days later while I was taking a bath, we were running a load of laundry and the toilet started bubbling again. Then the drainage from the washing maching started coming up through the drain in the bathtub and the toilet overflowed. My husband ran a snake down the toilet a number of times. We aren’t hitting any obstructions any more, so we called the city. They came and cleaned out their pipes yesterday and everything was OK until today. I took a bath and while the tub was draining the toilet started bubbling again. The tub stopped draining. I left if for about 1/2 hour then went back to check on it. The tub had drained and the water level in the toilet bowl had dropped below normal even though I hadn’t flushed the toilet. What’g going on?