I bought 8 books. So that was 8 carts. I did them all one at a time (load book to cart, checkout with coupon, look up next book, add to cart, checkout, repeat.). I never tried to click on my library. Of course it logged me out while I was gone and when I tried to sign back in I got the error. Tried to do a password reset, but that didn't work either. Then I remembered other people said they'd been locked out, too.
I still have 20 codes

The last one I got was in February. Mine all have LPE. (I bought a lot of Harlequin/Carina/Avon books last year).