Problem with predrawn line series even when model has no data

[IknowQT]

I don't know if anyone knows.
The chart and model are connected and the line series is connected with mapper.
If you add row and col to the table, the line series is already drawn.

I am appending real-time data to a table and I want the line series to be appended without updating.

Can anyone give me some advice regarding this issue?