Trains are no longer affected by a points failure at St Albans city station.
Earlier, trains running to and from Luton and St Pancras were being delayed, revised, or even cancelled.
Due to the problem, services to and from Sutton and St Albans were starting and finishing at West Hampstead Thameslink.
The disruption finished at 3pm.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here