I had to look this up, sharing so it might help others: Apparently "KYC" means "know your customer", and it is some sort of vetting process done by payment providers.
Anti Money Laundering is a ongoing process where you subscribe to a service that searches and monitors different lists for the name and birth year of all your customers. It raises a flag for a fuzzy match. The lists range from sanctions and terrorism which should immediately freeze the customer account, to adverse media such as financial crimes which is a judgement call depending on your service, to politically exposed persons or PEP which means to be cautious about transactions that could be improper use of public funds.
You will never be told if any of your transactions are being reviewed. This is done so as to not tip off potential fraudsters.