This sounds like what happened to @HotRocks and I on at least 3 occasions.
The two most recent wipeouts were on day 14 and day 27 of copper if my memory serves. Before I know the other time or two it’s happened was also during the 30 day copper period.
With velvet as common as it is now, not treating in copper or CP isn’t really an option either.
Ouch!!!


