SUMMARY

When trying to RIP an audio CD with lame and varible bitrate, the output fives always have a bitrate of 128 kbps, no matter how I configured the plug-in settings.

STEPS TO REPRODUCE
1. Open K3b Settings and go to Plugins tab.
2. Select Lame MP3 Converter and open it's configuration dialog (the button to do so has no label by the way)
3. Change the Quality settings to Variable Bitrate (no upper or lower limits, no average) with Joint Stereo.
4.  Not sure if it make a difference but I also set the quality to 9 (highest) in the advanced tab (which is by the way also strange, as the LAME manual says that 0 is highest and 9 is fastest)
5.  Press OK and close the K3b settings.
6.  Enter an audio CD and go to More Actions -> Rip Audio CD
7.  Select start ripping and select "mp3 (Lame)" as a filetype
8.  One more observation on the site: When clicking the "..." button next to the filetype drop-down and editing the Lame settings I get a similar dialog to edit the lame command line, as I was used to with when still working with Ubuntu 16.04. The command is by default set to 
    ```
    lame -r --bitwidth 16 --little-endian -s 44.1 -h --tt %t --ta %a --tl %m --ty %y --tc %c --tn %n - %f
    ```
    and does not change when I update the Lame settings in the plugins settings. It also does not make any difference when I add `-v` here manually.
9.  Start Ripping

The name of the buttons might differ a little, since I am using the German locale and the actual English labels might differ from my translation.

OBSERVED RESULT

Checking the generated output file:
```
file Audioslave\ -\ Out\ of\ Exile\ -\ 01\ -\ Your\ Time\ Has\ Come.mp3 
Audioslave - Out of Exile - 01 - Your Time Has Come.mp3: Audio file with ID3 version 2.3.0, contains:MPEG ADTS, layer III, v1, 128 kbps, 44.1 kHz, JntStereo
```
shows that it always has a bitrate of 128 kbps.

EXPECTED RESULT

A *.mp3 file with a variable bitrate :-)

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Ubuntu 18.04 bionic (x86-64) with Cinnamon 3.6.7
KDE Plasma Version: not installed (bionic offers kde-plasma-desktop 5:100ubuntu2 though)
KDE Frameworks Version: kde-runtime package is installed in version 4:17.08.3-0ubuntu1
Qt Version: 5.9.5

ADDITIONAL INFORMATION
The problems have been observed on Ubuntu 18.08 LTS with K3b 17.12.3 and LAME 64bits version 3.100.