i'm using pulumi in CI, in a pipeline where i have nightly, staging, and prod jobs. the staging job triggers after nightly finishes, and i'd expected that once a

pulumi up

has finished, it unlocks the stack. this doesn't seem to be the case; the staging job gets a 409 error. is this a bug, or a known problem with app.pulumi.com's concurrency management?

That is not expected behavior, no. Not a known problem either. Can you share the full error output you're getting? Are your nightly, staging, and prod jobs using different stacks?