Sources told TV Blackbox that the problems were nationwide and had hit live programming across Australia.
The technical issues also mean the network had been unable to prep each programme, throwing the channel's 6pm news bulletin into question.
However, a spokesperson for Nine said the network would be resuming live programming soon.
"Nine is responding to technical issues affecting live broadcasting. At this stage we are working through the impacts across the network and will provide an update as we resolve the systems," the spokesperson said.
"NRL, 6pm News Bulletins and our evening schedule will proceed as normal."
Entertainment reporter Peter Ford said engineers were investigating if the issue was a cyber attack.