Why is the edit button greyed out for me?
By now it should not be grayed out anymore.
The reason it was grayed out then ought to have been that there was a pending suggested edit by an other user already; in all likelihood this one.
Once there is one pending suggested edit, further suggestions are not possible as the ensuing conflicting proposals will be difficult to resolve.
For users that can review suggested edits the edit button will lead to the review task in such a case (and there is a number in parenthesis next to the 'edit').