When using the Lync Client to “Schedule a Meeting” with an internal contact the Scheduling Assistant page doesn’t provide Free/Busy information for the invited contact, unless the invite window sits open for over 5 minutes.

Reproduced this issue in:

• Lync Client 2010, Lync Server 2010, Exchange 2010
• Lync Client 2010/2013, Lync Server 2013, Exchange 2007
• Lync Client 2013, Lync Server 2013, Exchange 2013
• Lync Client 2013 CU1, Lync Server 2010 CU1, Exchange 2013 CU1
  
  

Workarounds to bring up Free/Busy immediately:

1. Uncheck and Check the Attendee
2. Check Name button
   
3. Ctrl + K (Check Name hotkey)
4. Clicking in the “To” Field then another location on the “Appointment” page, then switch back to “Scheduling Assistant” page
5. Book Lync Meeting directly from Outlook

In contrast using the “Send An Email Message” from the Lync Client, does a check name automatically within a few seconds.