use local farm network

 
Goodmorning everyone,
I have an unusual problem and it happens in a seemingly random way or:

data:
I have a farm with 50 agents around me, during the optimization phases, that some times they are used all a few times it is likely to use only those on the local computer, the one where I run EA.
the simultaneous check takes off the "use local farm network", I repeat this does not always happen but only sometimes, I read several articles on the forum but my problem is still unlucky ...
Thank you in advance for your interest.

regards
Marino