This just does not work in our environment, rather very annoying.
Tried adding various nodes all with certificates installed and every single one fails with the same error message
SSL Certificate Expiration Date Monitor Testing on node xxxxxxx:failed with 'Down' status
SocketException caught. SocketError: Connectionrefused. Exception message:No connection could be made because the target machine actively refused it xxx.xxx.xxx.xxx:443
Not happy as SW states it works out of the box :-(