Currently, I can’t say what is going wrong. Could you please reproduce the issue in the demo above(reproduce => click the “Share” button => send me the new link?
I initially thought it was because the time interval between data was less than 15 minutes.
But I tried changing the end time of ID 2 and 3 as follows, and the issues did not appear.
{ "id":1, "start_date": "2020-06-29 09:31", "end_date": "2020-06-29 09:33", "text":"Front-end meeting"},
{ "id":2,"start_date": "2020-06-29 09:21", "end_date": "2020-06-29 09:35", "text":"Feed ducks and city walking"},
{ "id":3,"start_date": "2020-06-29 09:25", "end_date": "2020-06-29 09:35", "text":"Feed ducks and city walking"}