I just had the same thing happen to me.
It happens to all of us from time to time.
A 0 balance on all of your revolving accounts
gives FICO the impression that you're not using
your cards. This is why so many forum members
recommend keeping a small balance on at least one
of your cards. And if you create the impression with
FICO that you're not using your cards, then they assume
you're a short term risk so your scores drop. But the moment
your card reports a balance, you should recover some if not
all of those points. So try leaving no more than a 9% balance.
This is called the AZEO method - All Zeroes Except One.
I know. It's counterintuitive, right? You'd think FICO would
want us to report 0 balances on all of our accounts to prove
that we're responsible. But their algorithms are mathematical.
They lack the common sense of humans. So each month,
you will have to weigh whether or not you want to leave a balance
on one of your cards and see your scores rise, or just pay them off
to 0 and take a short term hit. We all face this predicament, so
you're not alone.
My pleasure. And you're right: "peculiar" is the right word.
Just think of it this way: if you give FICO what they want,
they'll give you what you want - the highest scores possible.