ProxyAddresses is an array in Get-AzureADGroup , so doesn’t export to CSV nicely “System.Collections.Generic.List`1[System.String]”

Heres how to export and flatten the array

Get-AzureADGroup -All $true | Select DisplayName, @{Name="MyArray";Expression={ $_.ProxyAddresses -join "," }} | Export-Csv C:\Temp\Groups365.csv