In order for Acquia to have access to your private key, which is required to move forward with Acquia's technology refresh, we are asking your team to please re-install your Legacy SSL certificate in the UI again but this time leaving the “Install Legacy certificate” option unchecked. Doing so will not have any impact on your application.
As a reminder, Legacy certificates refer to SSL certificates deployed to an ELB on our platform. Additionally, Standard/non-legacy certificates are SSL certificates deployed to load balancers.
We have additional instructions on installing certificates in the UI here:
https://docs.acquia.com/acquia-cloud/manage/ssl/cert/#cloud-install-ssl-cert
Once you have completed this, please let us know by responding to the notification ticket we sent you so that we can proceed with scheduling your tech refresh migration.