Setup WPA4 for Varnish in PDP mode and let the server to process unauthenticated POST requests without completing authentication sequence (lots of them). AM_PDP_DIR should have accumulated large number of PDP temporary files. Stop Varnish server and try starting it again.
Expected: server startup completes immediately.
Actual: Varnish CLI will timeout and control process will kill the worker process.
Workaround: remove PDP temporary files manually before starting Varnish server.