If you try to change your password on the Fido web site to one that includes dashes, such as "h4U-3T5-eR7", you will get an error that says, "Please include at least 1 number and 1 letter."
So the bug is that the error message makes no sense. It should say, "The character '-' is not permitted".
But my request/suggestion is that dashes be a permitted character.
Otherwise it's cumbersome to use Apple Keychain to set a password on Fido.ca
Additionally, when iOS 11 comes out, I hope that the Fido app will support "Password Autofill for Apps".
** Edited to add labels **