Yes, such locks exist, and are actually sold in the real world. They are often used in "outdoor key storage", which will find you images of what they look like. Though I can't guarantee any particular model has this particular PIN flaw (some are even worse, such as only allowing a single number from each row).

Which is a limitation from the mechanics of the mechanism used. Including such a restriction on an electronic PIN is stupid, but I've seen enough idiotic password policies that I don't doubt someone has done it. For example, my bank (at least 2 months ago, haven't tested recently) makes no distinction between case of letters, so 'aaa' = 'aAa' = 'AAA'.

It's considerably worse when you see bizarre password restrictions because they usually mean the password is stored in plaintext. For example, your bank definitely is doing that.

Don't use that same password for anything else!

Over the phone with my bank and my cabal company I've had them ask me multiple times to confirm my PIN or give the answer to my security question. I'm shocked that they will store everything in plain text like that AND give a large number of their employees access to it.

I would prefer it be more explicit and say, "each digit can only be used once".

Different can be interpreted in multiple ways.

Reminds me of a physics test where the question is something like:

Susie is almost at her house and comes to a stop in 4 seconds. What was her acceleration.

The only other interpretation that is obvious to me is "not all of the digits can be the same", but 990 is not an available answer.

Well, my bank tells me that I can't have 3 equal digits in my debit card PIN.

The android lock screen, for example.