Why does master verification take a long time in mongodb replica?

Question

MongoDB

Here is a query that runs very slowly
[01:07:39] Roman T.: Tue Mar 25 15:45:41.697 [conn624456] command admin.$cmd command: { isMaster: 1 } ntoreturn:1 keyUpdates:0 reslen:441 1039ms
Tue Mar 25 15:45:41.697 [conn632048] command admin.$cmd command: { isMaster: 1 } ntoreturn:1 keyUpdates:0 reslen:441 1039ms
Tue Mar 25 15:45:41.697 [conn627860] command admin.$cmd command : { isMaster: 1 } ntoreturn:1 keyUpdates:0 reslen:441 1039ms
Tue Mar 25 15:45:41.697 [conn624876] command admin.$cmd command: { isMaster: 1 } ntoreturn:1 keyUpdates:0 reslen:441 1039ms
Tue Mar 25 15:45:41.697 [conn624273] command admin.$cmd command: { isMaster: 1 } ntoreturn:1 keyUpdates:0 reslen:441 1039ms
Tue Mar 25 15:45:41.697 [conn629711] command admin.$cmd command: { isMaster: 1 } ntoreturn:1 keyUpdates:0 reslen:441 1039ms
Should take approximately 0 ms to complete.