When running a sweep with grid search, some of the runs crashed. So I deleted these runs from the dashboard and use the sweep ID to run the sweep again. However, it will only launch jobs for runs that never started. If a run has started, regardless of whether it succeeded or not and whether it was deleted or not, the agent will not receive corresponding parameters from the server hence there is no way to rerun. When all runs are launched (and killed immediately), the agent will just wait for job indefinitely.
A quick way to test: launch any sweep with 3 runs, then launch the agent to run it then kill it immediately 3 times. After that no new agent will receive any job.