System.Security.Principal.IdentityNotMappedException Catching all errors - powershell

Question

I am having issues with a try/catch block where the catch block for System.Security.Principal.IdentityNotMappedException is catching all errors regardless if they're of type System.Security.Principal.IdentityNotMappedException or not. The problem is when I move the try/catch block outside of the script into it's own for testing, the try/catch works as intended.
The try/catch is inside a for/each so they only thing I can think of is that the loop is somehow tripping up the try/catch block? The one error it loves catching is System.Management.Automation.RuntimeException.
Below is the test script I made that works as intended, but placed within the foreach doesn't:
I actually got the error to manifest with this:
foreach($x in Get-ChildItem){
Get-Acl "C:\fake"
try {
$Acl = Get-Acl
Set-Acl LiteralPath "C:\temp" $Acl -ErrorAction Stop
Write-Host "Access Rule Added" -ForegroundColor Cyan
}
catch [System.UnauthorizedAccessException] {
Write-Host "Insufficient Priviliege. Owner: $($Acl.Owner) ($_)" -ForegroundColor Red
}
catch [System.Security.Principal.IdentityNotMappedException] {
Write-Host "Invalid Prinicpal! ($_)" -ForegroundColor Red
$abort = Read-Host -Prompt "Abort? (Y)"
if($abort -ieq "Y"){ Exit }
}
catch {
Write-Host "ALL: $_" -ForegroundColor Red
}
}

Answer 1

This isn't exactly an answer to my question (as I don't fully understand why it was happening and as such it might snag on something else) but adding -ErrorAction SilentlyContinue to the Get-Acl command that was throwing the first error helps prevent the errant catching:
foreach($x in Get-ChildItem){
Get-Acl "C:\fake" -ErrorAction SilentlyContinue
try {
$Acl = Get-Acl
Set-Acl LiteralPath "C:\temp" $Acl -ErrorAction Stop
Write-Host "Access Rule Added" -ForegroundColor Cyan
}
catch [System.UnauthorizedAccessException] {
Write-Host "Insufficient Priviliege. Owner: $($Acl.Owner) ($_)" -ForegroundColor Red
}
catch [System.Security.Principal.IdentityNotMappedException] {
Write-Host "Invalid Prinicpal! ($_)" -ForegroundColor Red
$abort = Read-Host -Prompt "Abort? (Y)"
if($abort -ieq "Y"){ Exit }
}
catch {
Write-Host "ALL: $_" -ForegroundColor Red
}
}
Though it's strange how $_ doesn't display the actual error but just AclObject in this instance.