I have a match with weighting above the linking threshold why has it not auto linked?

I have a match with weighting above the linking threshold why has it not auto linked?

There can be several reason why a match exceeds the linking threshold but hasn’t auto linked:

1. There is more than one profile that exceeds the auto linking threshold.

2. There is an important matching attribute that doesn’t match, for example National Insurance Number – the score for firstname, lastname and email address have meant the user has exceeded the auto link threshold, however the National Insurance numbers are different which needs manual intervention to confirm if it is the correct link.