Hi!
When line chart has two consecutive values that are exactly equal then smooth option makes the line disappear after the data point previous to those equal values.
To reproduce - in the sample code at https://blazor.radzen.com/line-chart I changed for example the value of 2019-04-01 data point to be equal to 2019-03-01 data point. This causes the bug as soon as smooth option is turned on.