Streaming FIFA 17 with ReLive lags

Hello.

I'm very new to the live streaming "area" as I have never done something like that, so forgive me if I'm asking a dumb question but I'm really not into it.

Anyways, I wanted to stream a few Fifa 17 matches on youtube for my friends yesterday but it was basically impossible doing that in fullscreen mode as the game would just keep freezing. As I know I don't really have a top tier PC, I reduced some graphic settings and started the stream again, but the game was still freezing. After that I put the game in windowed mode and it didn't freeze anymore.

 

Now, since I find streaming in windowed mode quite annoying I want to know if this problem is related to my computer's specs or it is because of some wrong setting by my side.

My pc specs:

CPU: i5 6600 (boxed)

GPU: XFX RX 480 GTR Black edition 8GB (no OC, stock)

MOBO: ASRock H170 Pro4S

16 GB RAM, 7200 RPM HDD (no SSD)

 

I was streaming in 1080p60fps (was also playing in 1080 fullscreen, also tried bot capped/uncapped FPS and enabling/disabling Freesync), 7Mbps bitrate, 129kbps audio bitrate.

 

Thanks for your consideration!