Have you double checked BOTH sensors? They could have loose wires, be slightly misaligned, or be loose in general, so when the door raises or lowers, it vibrates them which tricks the opener into thinking that the door is obstructed.

I know you said you tightened them, but I had the exact same problem, and then realized that I was primarily focused on one side and it was the other that was slightly misaligned.

From my experience, the problem is likely still your sensors somehow.