Dunno. Maybe Pres. Trump (or someone on his behalf) has had a very quiet word with certain persons?
Maybe we will know the true story someday, but this is very curious. My own county in Texas just reduced its tally of current active COVID cases from > 4600 to 81.
When pressed, the Texas Dept of Health admitted that the bigger number was because they were counting cumulative cases. Somebody had apparently thought to ask the hospitals how many COVID cases they were now seeing. Answer was very few.