loss carried forward and personal allowance reduction

I am employed and self-employed. I have just logged into my personal tax account to check a few things, and seen that my personal allowance for this year has been reduced. The only thing I can think of is that for my last self-assessment tax return, I have carried forward a loss. The reduction in my personal allowance is similar to the amount of loss I'm carrying forward. I don't understand why this would be. Is there actually a link or just coincidence?

Hi
A loss would not reduce your tax code.
You would be better to call on 0300 200 3300 to have this looked at.
Thankyou.