Can't Convert Server Finder Reference to Alias

If the instruction

set myItem to POSIX file "/Volumes/serverName/folder/" as alias

doesn’t issue an error, it’s that the named item really exists.
May you post the log history returned by:

set myItem to POSIX file "/Volumes/serverName/folder/" as alias

tell application "Finder"
	properties of myItem
	--set the name of thisItem to "newName"
end tell

It’s supposed to return something like:
{class:folder, name:“Documents”, index:25, displayed name:“Documents”, name extension:“”, extension hidden:false, container:folder “" of folder “Users” of startup disk of application “Finder”, disk:startup disk of application “Finder”, position:{204, 152}, desktop position:missing value, bounds:{172, 120, 236, 184}, kind:“Dossier”, label index:0, locked:false, description:missing value, comment:“”, size:7.807010854E+9, physical size:7.807090688E+9, creation date:date “mercredi 21 mai 2014 à 18:23:17”, modification date:date “jeudi 25 juin 2020 à 19:12:23”, icon:missing value, URL:"file:///Users//Documents/”, owner:““, group:”(inconnu)", owner privileges:read write, group privileges:none, everyones privileges:none, container window:container window of folder “Documents” of folder "” of folder “Users” of startup disk of application “Finder”}

Yvan KOENIG running High Sierra 10.13.6 in French (VALLAURIS, France) vendredi 26 juin 2020 01:44:49

I searched in my archives.
Error -10006 is : errAEWriteDenied
which means that you aren’t allowed to write to the target, (here change its name).
You must ask the administrator of the server why you are facing such feature.
Maybe it’s a wrong setting but maybe there is a good reason to prevent you to do that.

Yvan KOENIG running High Sierra 10.13.6 in French (VALLAURIS, France) samedi 27 juin 2020 12:06:42