It seems they have placed you on an auto-downvote list because they believed your content was unauthenticated and/or generated by AI. Meanwhile, you have authenticated your content via Facebook, but it appears they forgot to disable the autovotes. Unfortunately, that's becoming a common issue here for many users - these 'curators' are quick to downvote content they find 'suspicious' but slow when they have to turn off the downvotes.
RE: Downvotes my posts