We just had our septic system repaired, a baffle was stuck, and pumped.
Toilet paper was undegraded or not sufficiently degraded and everywhere on top, off the inside of tank.
We use Rid X and so on.
So don't expect toilet paper to be thoroughly dissolved in our RV tanks.
Do flush the tanks well as we don't want prymids of stuff or paper.
It takes a bit to flush the tanks but I expect I will take a little longer from now on. I have watched the opaque elbow until I was sure it was clear, only to see clumps of paper and such come though in a mass. That was when we were parked for a long time and may have left the sewer hose open so no ptrssure was created to force things to flush out.