Example:

https://spruce.corp.mongodb.com/task/mongodb_mongo_master_enterprise_amazon_linux2023_arm64_all_feature_flags_sharded_collections_jscore_passthrough_with_config_transitions_and_add_remove_shard_0_linux_enterprise_patch_eee81e179aa37839be7396ba4eaa1b4ec48cd9f2_69cdde33df83ed00078cf160_26_04_02_03_10_54/tests?execution=0&sorts=STATUS%3AASC

This failed because shard_rs0 was uncontactable when inter-node validation was started, but based on the logs, rs0 should have been back (it was restarted when the test completed and the validation hook started, according to logs)

So it is unclear why the shard gave this error.