Reversal sale from last 2 months

Yesterday 24 Nov 2020 and today 25 Nov 2020, i received reversal for 2 my sale:

1 sale from 17 Sep 2020, 1 sale from 27 Sep 2020

I worry about the rights for author

Why sale in 2 months ago and receive reversal?

In the majority of cases, purchases can be liable to reversal up to 120 days from purchase.