Home Sharing problems

Hello,

Home Sharing is not working properly on my third generation Apple TV. The Remote App works, but, my Apple TV can't connect with my computers (Macs or PCs). It even can detect them. Home Sharing usually worked fine, but, it suddenly stop working without reason.

I've done everything Apple says in their troubleshooting documentation, but, it still doesn't work.

My iOS devices experience the same issue than the Apple TV. My computers can use Home Sharing between them.

All the software is up to date.

Thank you for helping me.