Update: the error belongs, indeed, to the RKI crew: https://twitter.com/Tim_Roehn/status/1477975486764572675
Via Google translate: "Update: The RKI made a significant change in the weekly report 4 days after publication (see below). Now there are 1097 instead of 186 unvaccinated people, so the proportion of those who have been vaccinated is significantly lower. // @world"
Edit: Update of the OA: https://twitter.com/holmenkollin/status/1477970997638676483