Unset labels inherited from previous line

I configured promtail to export logs for two jobs:

  1. systemd, including a dynamic unit label, and
  2. a file, with no dynamic labels, and in particular no unit

All works when I try --dry-running it.

But when I actually run it and look it up in Loki, I see that the entries for the job 2. also have unit labels, equal to the unit of the previous log line of job 1.

Not sure if this is the same behaviour as described here: promtail uses previous unit label for dmesg messages · Issue #2660 · grafana/loki · GitHub

We are running 2.5.0.

Anyone else with this issue? Am I doing something wrong?