I had similar issues when trying to purchase my seats.The inexplicable fix was:Don’t search for the show you want. Run the search by a set of dates, for example, the day before your show to a week after. Click to next performance - until you get to your performance. Select your seats, buy.Worked for me
Hadestown has been going live around noon, a little after. I got tickets for tonight yesterday at around 12:10. It then disappeared and reappeared for a brief time around 1. This was the same time frame for when they released on Monday for Tuesday/Wednesday.