We lowered a rate limit in a ConfigMap, Argo CD reported Synced, and the service kept using the old limit for two days. Environment variables from ConfigMaps are read once at container start, and our file mount used subPath, which never updates. A checksum annotation fixed rollouts.
Every deploy of one service failed with another operation is in progress after someone cancelled a pipeline mid-upgrade. The release was stuck in pending-upgrade. We recovered with helm rollback, then added CI concurrency, timeouts and atomic upgrades so it cannot recur.
Half our Argo CD applications showed OutOfSync seconds after every successful sync, and auto-sync kept fighting the HPA over replica counts. The live objects had fields set by controllers and webhooks that Git never mentioned. Targeted ignoreDifferences and server-side diff fixed it.