Different durations per service

Dear Sirs

I have your Appointment+ v. 1.17 version and just updated to the newest version.

I have the time base set to 30 min. I also have a service with a 30 min duration.

I have now tried to add a new extra service on 60 min duration for certain service providers, but then the service providers with the 60 min service does not show up in front-end (you cannot choose them)

Can you help me to obtain different duration times for each service provider.

I have 6 providers and 3 of them need 30 min and the other 3 needs 60 min.