On SharePoint 2013 farm, we have deleted approx. 1000 site collections previously and when we installed Jan 2021 CU on SharePoint 2013 farm approx. 300 site collections again reappeared in farm and those sites accessible properly.
We have deleted again them but that is very strange why and how they reappeared again in farm after CU activity.
We used to do CU activity every 3 months but first time we faced this issue.
Any one have faced this type of issue or suggestions please.