I have used Ccleaner for many rears. Have had same license code for a long time. Got a notice to renew, which I have done many times. So I clicked the Renew button. Got a new license code and lost the remaining balance of my existing license. If I use Manage License popup in Ccleaner it takes me down some Microsoft App path where I have to synchronize my whole Google account to something I don’t understand and not going to do. Is there a simple support contact to correct this?
The licence system changed a few years ago and the old style licences (24 characters) have been being gradually updated to new style ones (20 characters), so that may be what you are seeing.
When you do any renewal the time remaining on an old licence should automatically be added to the new one, but it may take a couple of days for that to happen when the licence numbers have changed.
If it hasn’t happened within a week then contact support asking for a “Licence merge” and giving the old and new licence keys.