See the bug report at the time. It was closed without being fixed and it was 100% reproducible. Maybe it's fixed now but no one was too worried about it then and I saw similar reports on the forums for a while before I lost interest. I should either try syncthing again or finally test infinit completely. This is the last piece of the puzzle I'm missing to have a fully workable personal data management solution that allows me to bring up a completely new laptop with my full config and data with just a clean Ubuntu install and a few commands.
https://github.com/syncthing/syncthing/issues/468#issuecomme...
Since that bug was closed with no solution I'm not too hopeful but maybe I should try it again.