If you notice Bob acting erratically, yet the results of his checkup test are normal, then you may need to reset his mainboard.
First, flip Bob's power switch OFF.
Next, unplug the power adapter from his charging station,
and plug it directly into the inlet on Bob's side. Bob's screen will light up, and his battery bars will flash.
Wait 15 minutes before unplugging Bob from his power adapter and flipping his power switch back ON. By now he should feel refreshed and ready to tackle the next cleaning adventure!