PowerShell: network-related or instance-specific error occurred while establishing a connection to SQL Server - sql

Question

On my Skype For Business Server, when I run the following command, my Queue get's changed as it should:
Set-CsRgsQueue -Instance $queue
On my linked server however (one hop away from the Lync server), i get the following error:
network-related or instance-specific error occurred while
establishing a connection to SQL Server. Set-CsRgsQueue : A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the
instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified)
I am however able to set up ODBC to the remote server (+ opened FW 1433 port, restarted the service ,....)
Where could my problem be?
EDIT:
My scriptblock looks like:
import-module Lync
$queue = Get-CsRgsQueue -Name $toChange
$action = New-CsRgsCallAction -Action TransferToPSTN -Uri $forwarduri -QueueID $queue.Identity
$queue.OverflowAction = $action
$queue.OverflowThreshold = 0
Set-CsRgsQueue -Instance $queue
If i'm not able to solve the issue, how could I implement invoke-command as this works on the server itself?
I tried by doing:
Invoke-Command -ComputerName SQLSERVER -ScriptBlock {Set-CsRgsQueue -Instance $queue}
but this throws:
Cannot validate argument on parameter 'Instance'. The argument is null. Provide a valid value for the argument, and then try running the command again.