Service name missing in task, present in powershell - powershell

Question

I have worked on a powershell script to check if certain important services are running on the server and email me the results. When I test the script and run it in powershell, the emails come through correctly. However when I set up the task on the server and have it run the script, the emails that arrive are now all missing the service names.
Email when the script is run in powershell:
At 12-11-20 11:06, the [service] is ALL GOOD on [server].
Email when the script is run through tasks:
At 12-11-20 11:00, the is on [server].
(services and server names redacted)
Any ideas on what syntax I'm missing that it works in the testing, but not in the actual execution?
My script code (with some details redacted):
$DateTime = Get-Date -Format "MM-dd-yy hh:mm"
#Check if service is running
$servName = "[service I need to check]"
$serv = Get-Service | Where-Object { $_.DisplayName -eq $servName}
$Subject =$Serv.Name + " check on [server]"
If ($serv.Status -ne "Running") {
$Body = "At $DateTime, the " + $serv.DisplayName + " service is " + $serv.Status + " on [server]."
}
Else { $Body = "At $DateTime, the " + $serv.DisplayName + " is ALL GOOD on [server]." }
[location]\EmailAlert.ps1 -Recipient me#work.com -Subject $Subject -Body $Body
$servName = "[another service to check]"
$serv = Get-Service | Where-Object { $_.DisplayName -eq $servName}
$Subject =$Serv.Name + " check on [server]"
If ($serv.Status -ne "Running") {
$Body = "At $DateTime, the " + $serv.DisplayName + " service is " + $serv.Status + " on [server]."
}
Else { $Body = "At $DateTime, the " + $serv.DisplayName + " is ALL GOOD on [server]." }
[location]\EmailAlert.ps1 -Recipient me#work.com -Subject $Subject -Body $Body