Bump chart sorting is broken

[eolay]

In which chart does the bug happen?

• Bump chart

RAWGraphs Version
2.0

Web browser and version

Vivaldi | 6.8.3381.50 (Stable channel)

Operating System
Windows 10 Pro x64

Steps to reproduce this
Select Test data "Foreign Residents in Milan"
Change format for the Date
Put the variables to the places: Date to Y, Residents to Size, Country to Streams
Couldn't change the sort type in the Series settings menu (I change it, but nothing happens)