Different options for service principal creation

Hello,

if I create a new service principal during Azure Arc deployment for multiple server and have no SPNs configured at this time I see the following screen:

If I clock on "Create service principal" in the middle and not on "Add" I get the following options for expiration:

And if I click on "Add" I have the option to use "Custom" as expiration:

Can someone tell me if this is by design?

Thanks in advance

Andreas