Random ssh error when fork above 2 even 1 - Unreachable hosts

[Anıl Dursun]

Hello,

I'm having random ssh fails with default fork=5.

I realized  it could be solved with fork=1 (not even 2 to be sure). 

I'm running playbooks that 

create dirs, 

copy a shell script (can take some time to complete)

execute it (i don't remember why I do it with shell module and not with script)

fetch output

delete the script and output file

Why in this environment even fork=2 is problematic? On what it depends?

I saw

grep -i MaxStart /etc/ssh/sshd_config

I can't access this value right now and I'd really want to have your opinion. 

Thanks in advance.