Check your availability calendar. I have it selected to keep dates unavailable by default and just discovered that my calendar was opened through May 2020 with my winter reduced rates.
That’s good advice.
And I plan to figure out how to make calendar rule-sets today. I haven’t been able to figure it out yet.
Users here regularly report blocked dates opening up on their calendars. One strategy that is suggested to be used on essential dates (like my vacation to NZ) is to raise the price to something no one would book, then block the dates.
Or just raise it to a price not only would no one likely book, but if they DID then you would be willing to change your plans to be able to accommodate them!