The cause of the problem was that the installed Windows platform product version on the clients was too old. After the release of a new Windows Defender platform version, support for older versions (N-2) is reduced to technical support. Platform versions older than N-2 are not supported. To fix the problem, the new Windows Platfor Update (updateplatform_x64.exe) had to be downloaded manually and installed on the affected clients.
Update for Microsoft Defender antimalware platform can be found here.
The new Windows Platfor Update (updateplatform_x64.exe) then can be deployed via MECM either as a Package or as an Application.