OpenModelica Bug: Multiple display unit changes in plotting with prefix unit

Description

When a display unit is changed multiple times in the plotting window the value is in a prefix unit (e.g. krpm) but the legend displays the base unit (e.g. rpm). Soryy for duplicate if this is already part of another plot unit related issue but I could not find an issue directly addressing this bug.

Steps to Reproduce

Simulate the following model with the Prefix Unit option activated:

model PlotUnitError
  Modelica.Mechanics.Rotational.Components.Inertia inertia annotation(
    Placement(transformation(origin = {10, 10}, extent = {{-10, -10}, {10, 10}})));
  Modelica.Mechanics.Rotational.Sources.Speed speed annotation(
    Placement(transformation(origin = {-30, 10}, extent = {{-10, -10}, {10, 10}})));
  Modelica.Blocks.Sources.Ramp ramp(height = 1000, duration = 1)  annotation(
    Placement(transformation(origin = {-70, 10}, extent = {{-10, -10}, {10, 10}})));
equation
  connect(speed.flange, inertia.flange_a) annotation(Line(points = {{-20, 10}, {0, 10}}));
  connect(ramp.y, speed.w_ref) annotation(Line(points = {{-58, 10}, {-42, 10}}, color = {0, 0, 127}));

annotation(uses(Modelica(version = "4.0.0")));
end PlotUnitError;

Change the display unit of inertia.w to rpm and plot it. The plot looks as shown in the first screenshot (unit in legend = krpm and a ramp from 0 to around 9.5, which is correct)
Change to display unit to rad/s and then back to rpm. The plot looks as shown in the second screenshot. The value range is the same but the unit listed in the legend is now rpm instead of krpm, which does not fit to the displayed values.