If "ignore" was clicked during a merge in the past, these will not be recognized as duplicates.
To correct this, create the customer again. (Name and/or email + phone number) This means that with the ignored suggestion, three duplicates exist.
After that, the ignored suggestion will be displayed.
Please note that merging customers cannot be undone and should therefore be checked carefully in advance.
Simply click on the X and merge.
After successfully merging, it is recommended to briefly check the remaining customer entry to ensure that appointments and contact information have been completely transferred.