POWERSHELL TRYING TO PRINT PATH OF FILE IF STRING FOUND

I am trying to print the path of a file if string is found. Problem is if 1 file does not contain the string in a folder then I do not get any output. Basically I am looking to see if a certificate epoch-time is within 30 days of expiration. Below is my code:

$c = Get-Date (Get-Date).ToUniversalTime() -UFormat %s
$epochtimes=[math]::Round($c)
$d = get-childitem C:\scripts\PALO\* -recurse | Select-String -pattern 
"expiry-epoch"
$e=$d -split "epoch"
$certtime=[double] $e[1]
$certexp = $certtime - 2592000

ForEach ($i in $certexp){
If ($certexp -le $epochtime) {
Write-Host $i
}
}