Get-ADUser cannot get data from my variable

Hi have a really strange problem using get-qaduser.

Here is the script that I am using:

$Source = "C:\Temp\Source.txt"
Connect-QADService -Service "ActiveRolesServer" -Proxy
ForEach ($UPN in GC $Source)
{
Get-QADUser -identity $UPN | Select-Object -Property UserPrincipalName,MobilePhone

This is the result I am getting:

When trying the query I get nothing in return.

When running $UPN alone I get the last name in my $Source variable, which is good.

When running the script replacing the $UPN by user@upn.com, all is good

But when running the query from the script the result is empty.

Any idea?

Also, when running it from another computer, the script is working like intended.