Hi Vilem,

Thanks for reaching out to us. Please find the answers below

Issue 1) Our employees are synced with Google Calendar. One out of 20-30 appointments is not synced. This happens randomly amongst multiple employees. Is there any logfile where we can see what happened ? Since this issue occurs randomly it is very hard to troubleshoot without logfiles.

This usually happens because the maximum number of events returned per page is not increased. It is usually enough to keep it on 50, but increasing this number to a higher value usually helps in Google Calendar reading all the appointments from Amelia. You can find this option in Google Calendar settings. Please note that you need to enabled "remove busy slots" in order to increase the number of events.

Issue 2) Sometimes we got double booking for the same employee and the same time. Seems like a coincidence when two customers are submitting the booking at the same time, but is there any way how to prevent this ? 

In theory, it could happens that two customers are booking the same timeslot at the same time. While this is rare, it could happen, but perhaps this could be an issue due to the fact the configuration will allow your customers to do so. That being said, if one service has maximum capacity configured to 2 or more, and the option "Allow booking below minimum capacity" in Appointment settings is activated, your customers will be able to book the same timeslot multiple times. So, you want to double check this. 

I hope it helps.