A few days ago, my bathroom drains started acting strange. When I ran my sink, the toilet would bubble. So I took a hose up a ladder and put water down the vent to see if maybe it was clogged. I ran it for at least 20 minutes and nothing happened. It did not back up, and it did not help the toilet situation. However, now that I have done that to the vent, the toilet does not bubble anymore it just doesn't flush. I replaced the toilet itself and checked the pipes in the crawl.. all is good. I also had a plumber come out and snake the toilet both with the toilet in place and with removing the toilet and going straight at the drain. This did not help either. Nothing has ever come up any of the drains, in fact the washer, dishwasher, kitchen sinks drain very fast with no issues. The bathroom tub, sink and toilet is where the issue is. The bathroom sink and tub drain rather slow, but drain nonetheless. The toilet will very slowly try to flush but gets to the point where it should suck all of the water and waste down it does not have any suction or pull, instead it slowly goes down a little bit and then sits there. The bathroom drains are the last to dump into the main drain before making it way to the sewer. Could I have an issue in that area?

When the plumber was doing all this snaking did he snake from the roof vent, A garden hose doesn't do the job a auger does. Do you use bluing od bowl cleaner in your toilet tank? Check the jet,( the small hole in the bowl) and see if it's clear. Back to you. Tom