When a client books an appointment, they receive a confirmation email which contains a .ICS file that can be opened to quickly add the meeting details to their personal digital calendar. This currently works well for all of my clients.
When a client uses the "Reschedule" feature of Zoho Bookings to change the date/time of their existing appointment, they receive a revised confirmation email that contains a revised .ICS file which in most email programs can be opened to quickly update their existing meeting details in their personal digital calendar. However, I have noticed that if a client opens the revised confirmation email in the default Mail app on iPhone, only the original meeting details are displayed when they tap on the .ICS file. There is therefore no way for a client to easily update the event in their digital calendar to reflect the rescheduled meeting details. This seems to be a bug specific to Apple Mail on iPhone, but perhaps the Zoho Bookings team can review to see if they can recreate the issue and if there is some way to modify the booking details within the .ICS file to ensure it works properly on iPhones?
Given the popularity of iPhone and Apple Mail, hopefully this is an issue that can be addressed with urgency. If not, please reach out to Apple support on behalf of call Zoho Bookings users explaining the technical issues around the way their software operates so that they can make any necessary changes.