Here is an issue I just experienced myself. I created a new wallet and noted down the passphrase. verified it twice. Then i selected keywords in right order to verify passphrase. Then my new wallet opened and i copied the address to send cardano to my wallet. Just before that, I stopped. i decided to restore wallet.
I entered passphrase using restore wallet option and it said that passphrase is not valid. WTF!!
so, here I think what happened. I missed some letter in passphrase even after checking twice. so, the step of verifying passphrase by clicking each word in passphrase is bad way to verify passphrase. you must type in manually.
My 2 cents…or 2 ADA…if you like that.