node worker for loop slow between first and second iteration

I have a method that contains a for loop, and I have the main process and child processes calling this method.

20404 create:  2022-01-14 05:44:10.073
20404 create:  2022-01-14 05:44:10.075
20404 create:  2022-01-14 05:44:10.077
20404 create:  2022-01-14 05:44:10.077
send: 2022-01-14 05:44:10.078
send: 2022-01-14 05:44:10.079
send: 2022-01-14 05:44:10.079
16228 get  2022-01-14 05:44:10.081
11976 get  2022-01-14 05:44:10.081
9692 get  2022-01-14 05:44:10.082
11976 create:  2022-01-14 05:44:10.087
9692 create:  2022-01-14 05:44:10.087
16228 create:  2022-01-14 05:44:10.087
16228 create:  2022-01-14 05:44:10.113
9692 create:  2022-01-14 05:44:10.114
16228 create:  2022-01-14 05:44:10.116
11976 create:  2022-01-14 05:44:10.116
9692 create:  2022-01-14 05:44:10.117
16228 create:  2022-01-14 05:44:10.119
11976 create:  2022-01-14 05:44:10.121
11976 create:  2022-01-14 05:44:10.123

Above are logs, send is when main process sends the instruction to child process.

The first four lines are printed out from the main process, 2ms on average between every iteration

get is when a child process gets the instruction.

The first number is the process id. As you can see at this part:

11976 create:  2022-01-14 05:44:10.087
9692 create:  2022-01-14 05:44:10.087
16228 create:  2022-01-14 05:44:10.087
16228 create:  2022-01-14 05:44:10.113
9692 create:  2022-01-14 05:44:10.114
16228 create:  2022-01-14 05:44:10.116

The time gap between those two iterations is huge compared to the rest time gaps. Any ideas why this is happening?