The following seven tests consistently cause host timeouts on sharded clusters, as well as rarely on replicasets and standalones:

test_retryable_reads_in_sharded_cluster_multiple_available, test_retryable_writes_in_sharded_cluster_multiple_available, test_callback_not_retried_after_commit_timeout, test_callback_not_retried_after_timeout, test_callback_returns_value, test_commit_not_retried_after_timeout, test_in_transaction_property.

For example: https://spruce.mongodb.com/task/mongo_python_driver_test_rhel8_py3.13_auth_ssl_cov_test_4.2_sharded_cluster_patch_c2338d879b1ccd37eb5d970c8f8be97674a9a252_6716737ef917630007a3376e_24_10_21_15_30_47/logs?execution=0&sortBy=STATUS&sortDir=ASC