It's working fine for me in v4. If you want the filament properties to change with the material drop-down list selection, you have to configure it that way.
Go to File > Export FFF Profile, save your profile to your hard drive, and then open the .fff file in a text editor (it's just a standard XML file). Scroll towards the bottom and look for the <autoConfigureMaterial> sections. You need to add the filament settings (in bold) into each of those sections like this:
<autoConfigureMaterial name="PLA">
<globalExtruderTemperature>230</globalExtruderTemperature>
<globalExtrusionMultiplier>0.9</globalExtrusionMultiplier>
<fanSpeed>
<setpoint layer="1" speed="0"/>
<setpoint layer="2" speed="100"/>
</fanSpeed>
<filamentDiameters>1.75|1.75|1.75|1.75|1.75|1.75</filamentDiameters>
<filamentPricesPerKg>46|46|46|46|46|46</filamentPricesPerKg>
<filamentDensities>1.25|1.25|1.25|1.25|1.25|1.25</filamentDensities>
</autoConfigureMaterial>
<autoConfigureMaterial name="ABS">
<globalExtruderTemperature>230</globalExtruderTemperature>
<globalExtrusionMultiplier>1</globalExtrusionMultiplier>
<fanSpeed>
<setpoint layer="1" speed="0"/>
</fanSpeed>
<filamentDiameters>1.75|1.75|1.75|1.75|1.75|1.75</filamentDiameters>
<filamentPricesPerKg>46|46|46|46|46|46</filamentPricesPerKg>
<filamentDensities>1.25|1.25|1.25|1.25|1.25|1.25</filamentDensities>
</autoConfigureMaterial>
and so on until you get to the last <autoConfigureMaterial> section. I had 4 sections, so you have to add those 3 tags into each section.
Then save the file, go to File > Import FFF Profile and load it back into the software. You only need to edit the text file ONCE. After that, you can change the filament settings in the UI and they now save correctly with each material