Duplicate addresses for NAS

Apparently, I have 2 working addresses for my Synology NAS.  Router login.net only finds one of them 192.168.1.23. My new music player finds that as well as 192.168.1.30. I did verify that I could login to the server with both addresses via Safari. I didn’t think this could happen. I cannot find a way to delete the 192.168.1.30 address. Does anyone have a clue ho to fix this?

Thanks in advance.