No need to use /beta, that's already available in /v1.0. Both endpoints work fine for me, but you can expect null values for users that have never logged in. Other than that, check the scopes in your access token.
is the signInActivity and lastpasswordChangeTime no longer available in graph beta or am I doing it wrong?

Forgive me, graph is new to me.
I've cobbled together the following script to pull data from graph beta using the select method. I do not get an error, but the result is pointedly missing anything in the resulting signInActivity and lastPasswordChangeDateTime fields. I think the registered app has the appropriate permissions or else it would have an error, right?
I followed some info I found here (and a couple other similar): https://www.michev.info/Blog/Post/2968/reporting-on-users-last-logged-in-date-in-office-365
Anyway, here's the script (with the domain, secret, and clientID randomized for safety, 'natch)
$clientID = "this-is-where-clientID-would-go"
$clientSecret = "this-is-where-secret-would-go-even-though-that's-not-good-form"
$tenantDomain = "my-domain-name-here.onmicrosoft.com"
$loginURL = "https://login.microsoft.com"
$resource = "https://graph.microsoft.com"
$body = @{grant_type="client_credentials";resource=$resource;client_id=$ClientID;client_secret=$ClientSecret}
$oauth = Invoke-RestMethod -Method Post -Uri $loginURL/$tenantdomain/oauth2/token?api-version=1.0 -Body $body
$uri = "https://graph.microsoft.com/beta/users?$select=accountenabled,signInActivity,createdDateTime,lastPasswordChangeDateTime"
$ReportData = @()
$HeaderParams = @{
'Content-Type' = "application\json"
'Authorization' = "$($OAuth.token_type) $($OAuth.access_token)"
}
do {
$Results = Invoke-RestMethod -Headers $HeaderParams -Uri $Uri -UseBasicParsing -Method "GET" -ContentType "application/json"
if ($Results.value) {
$ReportData += $Results.value
}
else {
$ReportData += $Results
}
$uri = $Results.'@odata.nextlink'
} until (!($uri))
#this line would export to csv
#$ReportData | Select-object -property userPrincipalName,accountenabled,signInActivity,createdDateTime,lastPasswordChangeDateTime | Export-Csv .\AZ-Report-AzureUserAgingAndUse.csv
#This line will show to screen
$ReportData | Select-object -property userPrincipalName,accountenabled,signInActivity,createdDateTime,lastPasswordChangeDateTime | Out-GridView
Here's a sample of what I get:
Any ideas?