After successfully replacing the certificates manually on SDDC fails to fetch the certificates details; the certificate options are greyed out and there will be no option to generate certificates via the GUI.
VMware Cloud Foundation 5.2.1
Generate certificates via API using the below commands.
1. PUT /v1/domains/id/csrs
2. PUT /v1/domains/id/certificates
3. PATCH /v1/domains/id/certificates
Note : Please make sure you have a snapshot before performing any actions.