Main line backup, plumbing help?

ok, I have a question if anyone could give any advice. the past week my toilet and tub are getting backed up. when you flush the water flows to rim of toilet and when I plunge it goes down but bath tub then fill with water and dirty stuff. my husband thinks it's a vent problem. he went on roof and snaked the vents and everything works great but he's had to do it almost everyday for it to work. also whentries I was clothes it backs toilet up as well. any idea what could be wrong?

Yes your main sewer sewer line to the septic or city street main has a blockage,
you need to call a professional with the right size sewer machine to clear line