Multiple things. Both Firmwares are terribly out of date.
Both are Connectkey, so unless they are set to DHCP, and registered on a Domain, so if this is showing red in your DNS settings you will be required to scan by IP address and not hostname.
Your screenshot shows a subfolder of escaneos that the folder properties does not show, so username may or may not have access to the escaneos folder.
Upgrade the firmware on the 5855 by using this tool , if that resolves the matter (Not related to anything mentioned above) then go on and update the 5955 with this tool. (No settings should be lost with either)
I can't test or verify that there is not a special characters issue as I can only test with an American keyboard.