"Given that they've been expanding fast historically and have been maintaining an impressive and increasing increasing cash flow throughout why has it fallen off a cliff now?"

In addition to general panic, mentioned by Rayvt, I'd suggest that the big money doesn't want to hold a stock that has two straight reductions in guidance (under a quite newish CEO, to boot), and has basically promised that any new signs of a turnaround in earnings trajectory are unlikely to materialize until 2024.

I like the stock as a 3-5 year hold, but I suspect the big money traders are speculating that we don't see a significant turnaround in price until management calms the waters and builds confidence in its ability to return to profit growth. And that won't happen without confidence-inspiring quarterly reporting.

That said, at some point it gets too cheap too ignore the possibility of a bounce. I haven't done the calculations, but I assume we're safely at 5 year lows after the inflation adjustment. At that time (5 years back until COVID), the stock was earning about $6-6.75 a share.