The fix there worked for a while. Re-starting TTS then “complained” of having a newer version, so replaced the version in docker-compose.yml and now I get the same message again, whichever version I use (3.18.1, 3.18, 3.18.0, latest). I restarted from scratch, to no avail.
I wonder if there is something wrong with a server somewhere (or access to one). I just reverted back to explicitly giving 3.18.0, and the init phase worked. And then going back to 3.18.1, still works fine. And specifying latest also works fine.