Trains between Lowestoft and Norfolk are being delayed or cancelled because of a points failure at Oulton Broad.
Train operator Abellio Greater Anglia says the line is currently blocked but expects services to return to normal during the afternoon.
The 13:48 from Lowestoft was the first train affected and was cancelled.
There also delays in Norfolk because of a fault with the signalling system between North Walsham and Cromer is causing trains have to run at reduced speed.
A survey by the consumer organisation Which? has rated a number of rail companies in the East of England as the worst in the country.
Abellio Greater Anglia has stiff competition from FirstGroup and National Express in the competition to run rail services in East Anglia.
Train companies across the region have begun cancelling services over the Bank Holiday because of a planned strike by Network Rail workers.