Why does mongodump runs on multiple secondary nodes?


We are running Mongodb 6.0.5 community edition with 3 nodes cluster and mongodump is being triggered remotely on the replicaset with readPreference=secondary. I was surprised to note that mongodump has been running on both the secondary nodes and it looks like its splitting the backup load between the nodes. though this seems to reduce the run-time, sometimes it better to leave one secondary ideal to avoid any issues and swap ready with primary.
is this new behavior in latest version and is there option to run the mongodump just on one secondary node and not both? is this documented somewhere?