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Thanks for checking and reproducing it. Considering that these issues around DL server stop/start transitions can be triggered introducing an additional DL server (EXT) makes me wonder whether this could become even more problematic as we add more DL servers (hierarchical DL servers?). Considering that unconditionally clearing dl_defer_running in dl_server_stop() seems to re-establish a clear state-machine workflow, I think we should go with that fix for now, so we can unblock the EXT DL server patch set. With that change in place, all the server combinations and sequences I've tested seem to behave consistently. We can always revisit preserving the short-sleep optimization later if we find a way to do it with stronger guarantees (and I'll keep investigating on this), but for now the unconditional reset seems like the most robust fix to me. Opinions? Peter / Juri? Thanks, -Andrea