Whether it was day or clay, the "Next" button will still be visible after you reach 12 characters. So the problem isn't a mis-typed word.
That's not necessarily true... there are "checksum" calculations done by Electrum making sure you have entered a "valid" seed with "valid" words etc... If you've mis-typed a word, it likely WON'T accept it as a valid seed and "next" will be disabled (unless you select BIP39 from options, which switches off the checksum validation).
I have tried "dog dog dog dog dog dog dog dog dog dog dog dog" (even with double space) and the next button became clickable.
That's because that works out to be a "valid" (old) seed... hence why the next button is clickable...
Change the last dog to "clay" and it'll still be a "valid" seed and next is clickable... now change it to "day" and see what happens
This is where shit really hits the fan, I found the 12 word seed in my room and tried to use it to recover the account but the "next" button stays grayed out and unclickable. I have tried different spellings and capitalization.
It is quite possible that you've got a 12 word seed from a different wallet and NOT from Electrum. Easy test for this is to create an offline copy of
https://iancoleman.io/bip39/ (instructions at bottom of the page) and then enter your 12 word seed into the "BIP39 Mnemonic" box... if it works and generates a bunch of addresses, chances are that it ISN'T an Electrum seed, but is a BIP39 seed from a different wallet.