I've made a video of the problem I'm having. At first the problem was the cistern wasn't filling however I reseated the siphon which has stopped the water running into the pan. Now the issue seems to be that after a flush, the ballcock is stopping the water entering the cistern until I pull it back slightly (13s and 59s in video) which then lets the (I don't know the name of the part at the top of the ballcock) 'fall' which then lets water into the cistern. It's a relatively new toilet at 3 years old.
If anyone can help that would be much appreciated.
Video:
If anyone can help that would be much appreciated.
Video: