Hello Daisuke,

Thanks for reaching out to us.

Please note that the official language of our support team is English, thus I would like to apologize in advance if anything is lost in the translation since we use Google Translate to translate your query.

Double booking can occur if two customers book the same timeslot at the same time. While this is rare, it can happen, unfortunatelly. Double bookings can also occur if you have enabled the option "Allow booking below minimum capacity" in Appointment settings, as well as if you have a maximum capacity of service set to 2 or above. In this case, the customers will be able to book the same timeslot for a service, until the maximum capacity is reached.

When you say "not reflected in calendar" do you mean the Google Calendar or ?

Hello Daisuke,

Please provide me a temporary WP-admin (administrator) user for your site where this happens, so we could log in and take a look ‘from the inside’ as that’s the most efficient way to see and resolve the issue. 

We do not interfere with any data or anything else except for the plugin (in case that’s a production version of the site), and of course, we do not provide login data to third parties. 

You can write credentials here just check PRIVATE Reply so nobody can see them except us.

Hello Daisuke,

Thanks for the information and for the links. Unfortunately, the access has been blocked. We are located in Serbia, so you might want to whitelist this country 

Hello Daisuke,

Thanks for the access.

Since the problem is the same on both sites, lets focus on troubleshooting on one site. You can make the same changes on the other one.

Regarding the Google Calendar issue. I've increased the maximum number of events in Google Calendar settings. From our previous experiences, increasing this number helps is displaying all events in Google Calendar.

The notifications setup is correct, we recomend using the SMTP settings. I've just send a test email and it does work properly, but i was also able to make a test appointment and all notifications were sent accordingly. It's hard to replicate the use case where the notifications are "sometimes working, sometimes not" since we can only find out the issue when the notifications are not working at all. Most probably, this is connected with the issue 1.

For the Cart feature, this could be also related to the issue 1, since not appointments were going to the Google Calendar and thus you were not able to see them.

Can you please check if it works with Google Calendar and let me know?

Hello Daisuke,

That's great to see! Thank you very much for the feedback.

Of course, keep me posted if the issue happens again or if you have any other questions or issues.