keyword missing

This week I have 4 pages that were ranked in the top 3 on the Google homepage missing, possibly due to the October core algorithm update. I saw that the algorithm deployment has just been completed. Have you restored the lost pages? Do I need to wait a few more days to observe?

I have an adult website. For the specific keyword "incest porn", I was in the 6th place on the first page and it was raising up. Then suddenly it dropped down and now it dissapeared completely. It has passed one month and I don't see it any more. What may be the problem