Toilet bubbles when washer discharges. Smells a bit sometimes. When toilet is flushed it blows back. Sometimes flushes slow. Had tank pumped out and it quit for about 2 weeks and then started back. Also checked distribution box and it was clean. Any ideas please help.

Toilets bubble a lot, when you initially flush it is pushing water through the rim into the bowl and the air trapped in there and coming from the bowl will bubble.
I suggest one ply paper and adjust the tank for maximum water in the tank and maximum water leaving as it flushes

It blows water past the lid. I'm pretty sure it's not normal.

Main line is clogged

Doug's correct. You have a blockage in the drain line that must be snaked. Good luck, Tom,

Thanks guys. I figured since it quit when I had the septic pumped it was from the tank and the junction box. So I took a chance on what you said. I rented a trackhoe and dug up the line. It went about 70ft down hill. It was cast and about rotten so I replaced it with sch40. Anyway that fixed it. So I figured I would say thanks for your help. You saved me about $300.

You saved me about $300. Send it on over and I'll split it with the other experts. (Just kidding! )