It's not clear to me exactly what they are asking. Are they saying that anything you create on company time belongs to them indefiniely? That's fairly commmon

It's not clear to me exactly what they are asking. Are they saying that anything you create on company time belongs to them indefiniely? That's fairly commmon in the UK and I don't have any stong feelings about it. Are they saying that anything you create after you leave belongs to them? That's definitely not OK, but it's not clear that's what they are saying.