Unhealthy ingestor on loki distributor ring

same issue here; we’re using the Helm chart loki-6.28.0 (app versoin 3.4.2), 3 replicas of the distributor with maxUnavailable=2, and 3 replicas of the ingester without zoneAwareReplication and our backend is S3.
There are no restarts or errors in ingesters (which the distributors supposedly consider unhealthy). What would be the cause here?
In Loki Distributor outbound traffic to ingester drop - Grafana Loki - Grafana Labs Community Forums, @tonyswumac’s questions suggest it could be a resource dimensioning issue?