I have a little experience with 800-Series, I can confirm that you won't be able to see their ip address from the other switches on the same network unless you enable LLDP on the 800-Series. You can do it through webview, under "L2 Features" you should find "LLDP Global Settings" or something similar, then set LLDP state to "enabled" and Apply. This applies to 08H20G4 but I think it's similar on all 800-Series switches.