Repeat OE error - pump works, not clogged, spin works intermittently

I have a Kenmore front load washer that has been giving the OE code with increasing frequency. The filter is clean. The pump works. The spin works. No clogs in entire drain system. Top of drain is not too high. The machine is about 8 years old. model 796.40272900. A light or heavy load could stop during the drain of a wash or rinse and give the OE code. I can turn the machine back on, select spin, and it may work fine. I have found lately that I must open the door, rotate the drum, then select spin for it to work. This seems like a sensor. I replaced the main board located at the back top of the machine because I had ordered it due to another problem, but this did not repair it. The other problem was not being able to get the machine to even turn on until it was unplugged for ~20 seconds or until an audible click is heard. No other parts have been replaced. Any ideas? Thank you. -andy