Unfortunatly, the way that SO is coded allows you to suggest an edit, then gives you a weighted approval vote. However, it does send an approval request, even though it immediatly accepts it. This checks with the server if you may send a request, then sends it or rejects it based on the server feedback.
Since it asks the server first, if all your approval requests for the day are used, then it denies automatically.
I agree, however, to skip the server test for remaining votes and automatically allow edits (maybe make them not count to the total? IDK how SO would approach this) if you posted the question/answer that you are attempting to edit.
NOTE: I do not know the exact method that SO is coded in, but rather I am using logic and programming experience to provide a likely method that would fit the facts that you have showed.