I once tried to use a 20-character password for iCloud, using letters, numbers and other symbols. It was rejected because it did not contain a capital letter. Sigh... I just capitalized the first letter and all of a sudden it was considered to be a great password, much better than the first!
Once you go past a certain number of characters, the system shouldn't care about capital letters and such anymore. Just calculate the total entropy with the number of different kinds of symbols and the total number of characters.
The other extreme, my internet provider actually limits passwords to 8 characters (minimum 6, maximum 8) and only allows letters and numbers. When I complained, they said they would forward my suggestion but that this was considered good enough security. It still hasn't changed.
Another example of programmer stupidity, Interactive brokers has two factor authentication with a double sided key card containing 224 codes, each being three letter/number characters like "A4T". It asks for two of those codes, so you would obviously expect them to take one from each side of the card to avoid someone being able to log in with a photo of one side of the card. Nope, half the time the codes are on the same side, and you can cancel and try again until it asks for two codes on the side you want. Even worse, sometimes it asks for the same code twice. Really?! Please enter code #135 and code #135?