What is going on in Arizona?

The Arizona Senate's audit of the 2020 election has uncovered several troubling issues, the least of which is the continued resistance from Maricopa County to the audit, refusing to fully comply with properly issued subpoenas.
What are they hiding? The election was legitimate, was it not? So why all the pushback? It is obvious that the American people were hosed, and Maricopa County participated in it.