Ongoing mass rating manipulation

For 2 months the ratings of Rezero were stable but suddenly just in 3-4 days every season's ep rating of Rezero has dropped. Rezero season 4 now doesn't have a single 9.7 rated ep and entirety of Rezero now only has 1 9.7+ rated ep which is also getting downvoted and would possibly drop soon (1x15)

Just 5-6 days ago it had ratings like: 4x8: 9.9 (now 9.6), 4x9: 9.8 (now 9.6), 4x10: 9.8 (now 9.5), 4x11: 9.9 (now 9.6), 4x12: 9.2 (now 8.8), 4x13: 9.9 (now 9.2).

Can any imdb staff please investigate into this and bring back the episodes to their original ratings

Title:  tt5607616