Losing Rendered Audio

I have seen requests about losing rendered audio in multi-cam sequences; however, I am losing audio in just a plain vanilla sequence. Is this normal?

1. Create a sequence (Seq-A) from a video clip (Apple ProRes 422)
2. Add (and align) in an external audio file.
3. Add audio processing to the external audio (not necessary to reproduce, but what I normally do)
4. Create a new sequence (Seq-B) from Seq-A
5. Select all in Seq-B (note, there are no audio waveforms in Seq-B)
6. Select all in Seq-B and render audio (audio waveforms now appear - good!)
7. Save the project and quit
8. Reopen the project. No audio waveforms in Seq-B (bad!)

I constructed a test project using exactly the above steps (rather than making assumptions based on my working projects), I had the additional feature of a red line through the audio on Seq-B when I reopened the project. This doesn't happen on my working projects which have all been converted from earlier versions of PP.

I am using Premiere Pro version 13.03 (build 9) on a late 2015 Macbook Pro, OS 10.14.3.

My media cache is on my internal SSD, the project and media files are on an external HDD. Media cache files are set to delete only after 30 days. My scratch disks are all on the internal SSD under  .../Documents/Adobe/Premiere Pro 13.0/

I hope that this will help Adobe reproduce the issue.