VEGAS Pro 18 x264 2 Pass ABR Doesn't run second pass

In Vegas Pro 18, when rendering x264 2 Pass ABR, Voukoder doesn't run the second pass. It just stops after the first pass and no render file is created. This works fine in the Premiere Pro/Media Encoder versions. I have checked the box for ABR "2 Pass" in the Voukoder settings. Is this a known issue or am I doing something wrong? Thank you.