Is your ground real sandy I can't get get the washers to drive in without bending or messing up in some way.
No our ground is hard baked red clay, about like concrete, lol. If you're bending washers your soil must be real rocky. Large rocks are about the only thing I've found that you can't drive pogos through. Sometimes the ground is so hard that each swing of the hammer only drives it in like a quarter of an inch and I'm cussing and sweating by the time I get it in, lol.
What size washers did you use? I've noticed the 2" ones bend way easier than the 1.5" ones do.