Have to restart Macbook to re-enable Internet Sharing?

So right now I'm using my 2013 rMBP (Yosemite) to receive my WiFi signal. I'm use Internet Sharing over Ethernet to connect my main desktop PC.

However, whenever I come back later to reconnect my MBP to my Desktop to get Internet, I always have to restart my MBP for it work.

Now the weird thing is, is that I only have to restart my Mac during the day; and not at night. My theory is that since none my connected devices on my network have static IP addresses, I think there is some sort of conflict between my Mac's internal IP and some other device on the network. I'm usually the only person to use any device connected to our network at night.