Amazon has changed it's Search Algorithm Resulting as KEYWORDS Disappear

An very old and well selling listing (sold over 6 years) has suddenly changed ASIN display from what is always to be as another old ASIN, ever since October 29th in Amazon front page.

Just like old ASIN disappeared from shopping results.

We wonder if there's any keyword restrictions come out to change display rules and caused anomaly keyword inclusion.

Since that day, majority of key words display changed cause a huge lost of orders and sales. There is no way that sales fall 50-70% within one day!.

Allegedly, they said there's something error with system match, or maybe search rules changed from that time. Hundreds sellers talking and mostly as best sellers.

Please help and investigate it ASAP!