An "audit" of ballots in Maricopa County, which may be happening illegally, and which is being run by a company with a QAnon-believing, Trump-supporting founder, is...to put it bluntly, a shit-show.
They've scanned ballots with UV lights to check for watermarks that Trump purportedly put on them, a conspiracy theory with no basis in truth (and a process that actually can ruin the ballots);
They've searched for traces of bamboo paper in the ballots, a racist theory that alleges China stuffed ballot boxes with pro-Biden votes (there's a thriving bamboo industry in Arizona, FWIW);
They used blue-ink pens to mark ballots, which can render them unreadable in voting machines when you run them through later on;
And they falsely accused election officials in the county of deleting data related to the election, when, in fact, the auditors were simply looking in the wrong computer drives.
Now, there's this (via NBC News):
Arizona Secretary of State Katie Hobbs said Thursday that the voting machines Republicans turned over to private companies as part of their audit of the 2020 election are no longer safe for use in future elections. In a letter sent to Maricopa County officials and shared with NBC News, Hobbs, a Democrat, cited security concerns about losing the chain of custody over the equipment when it was handed over to the auditors and urged the county to get new machines.
In other words, because the audit wasn't acting in a secure way from the get-go, and because the auditors handled the machines without proper oversight, there's no way to tell that they will work properly again or without interference/disruption of some kind (in the form of coding or something else) in the next elections they're involved in.
The cost to replace the machines will exceed $6 million — all for an audit that was never necessary in the first place.