This does appear odd.
You've got your entire PDGA tournament history going into your current rating, i.e. no old rounds dropped.
They dropped one "too low" round, but that was also dropped for the last ratings cycle too so that's not it.
Sometimes ratings will be adjusted or corrected later. I know this was the case with the Cool Cool Water at Quail Valley Links
tourney. The initial official ratings for that were very
wrong. But I was pretty sure they had those all corrected for the last ratings update.
Maybe one of the other past events you played was corrected in this update? You might want to drop a line to Chuck K. in this thread: