Get-MgBetaServicePrincipal returns wrong PreferredTokenSigningKeyEndDateTime values

[Jbmainson]

In order to get the expiration date of SAML certificates, i'm using 'Get-MgBetaServicePrincipal' to retreive PreferredTokenSigningKeyEndDateTime value for all the apps:

For some applications, the value returned by the cmdlet is not accurate:

The cmdlet Get-MgServicePrincipal doesn't return PreferredTokenSigningKeyEndDateTime property.

[Jbmainson]

Any news ?