The CDS team is actively investigating a technical issue impacting several datasets for which no selection can be made on the download forms.
In the meantime, access to data via CDS API is still available.
We recommend users to watch this post as we will update it with the latest information and when web access to the CDS datasets will have been restored.
We apologize for the inconvenience this may cause.
C3S Helpdesk at ECMWF