Halifax FTB Mortgage - Stamp duty included - Slow processing

Hi,

I am currently waiting on Halifax to get back to me on my first time buyers mortgage application. I am buying a house for £225k and have a £50k deposit. I did a full application on the 25th May and was fast tracked first, and then was asked for a whole load of other documents a few days later during the bank holiday. The survey was instructed and the money was taken straight away on the same day of the application.

I have been in contact with the bank a few days ago but they informed me that everything is still with the underwriters. Having had a look on my Experian account, I have an almost perfect credit rating. Halifax have performed two 'unrecorded credit enquiries'. Does this mean that they haven't done the official credit check yet or are they sometimes not performed?

It has been 3 weeks now since I applied. Is it normal for things to take this long or is it a sign that things are going wrong?

The length of time that everything is taking it starting to worry me. Any advice you can provide would be gratefully received.