Overmind 2.4.0 is only running the first entry in the Procfile?

[jmdfm]

I have a Procfile.dev that looks like this:

rails: bundle exec rails server -b 0.0.0.0 -p 3000
sidekiq: bundle exec sidekiq -C config/sidekiq.yml
clock: bundle exec rails runner bin/clock

I am running Overmind 2.4.0 inside a Docker container. It seems to only start the first entry of the Procfile correctly, and the other entries are marked as running but do not have a PID, and cannot be connected to.

overmind ps looks like this:

> overmind ps
PROCESS   PID       STATUS
rails     25        running
sidekiq   0        running
clock     0        running

If you try to connect you get the following error:

can't find window

I've tried moving lines around in the Procfile, and it always starts the first line entry only.

Is this a bug or am I doing something stupid? This does not happen with 2.3.0. The version of tmux installed is tmux 3.3a