Network rendering - not always seeing master

I set up a mini (or micro… or maybe pico…??) farm at home with two computers. One computer runs Windows OS and it has the master and a slave set up on it. The status web-page detects the slave so that part is working.

For development I run OS X and use that for the client. I enter in the master IP address and it will detect it, but within a minute or two, it will lose connection with the master. Trying to send a job once the master is detected, it will time out. Not sure what to do about it - if it can detect the master then obviously everything is set up correctly. I am not understanding why it loses connection to the master. If the Windows computer was turned off, then it would make sense - but that isn’t the case. Anyone one else seeing this issue and able to resolve it?