Please help me

I am new to this but have been using Serviio to stream movies from my PC to my Sony Bravia KDL-55W900A for over a year now without any problem. then I Upgraded to new Comcast router/modem and now have trouble with disconnection problems. Movies will run for 3.5-4 mins only then server disconnects. I tried reading more about this and I'm lost. I don't know what I'm doing and if anyone can help me please!
Now the only way I can watch a stored movie from my pc to the tv is to transfer the movie onto USB.
Any help is much appreciated.
Thank you
Now the only way I can watch a stored movie from my pc to the tv is to transfer the movie onto USB.

Any help is much appreciated.
Thank you