I would think if my receiver was the problem then turning the sub off and back on would not fix the issue every time - is that a flawed assumption?
Yes.
The sub automatically turns itself on when it senses an input signal. Often times, it won't do so with a weak or "soft" signal, so the idea is to boost the output of the receiver. This makes the receiver output a "stronger" signal to wake up the sub better. Of course, you then need to turn down the "volume" on the back of the sub so the total output is not louder. i.e., if you boost the receiver's output by 6 dB, you'll want to lower the subs "volume" knob by 6 dB.
When you turn your sub off and then on again, it automatically "wakes the sub up" so, in effect, it's not relying upon that signal from the receiver at that point.
