The comment broke the grace period.
According to ex-CM Shog9's answer,
Edits will be rolled into the previous revision if the previous revision was created by the same author and none of the following conditions are present:
The previous revision was created 5 minutes or more in the past
A comment has been added to the post after the previous revision by ...
FWIW, the -4 negative reputation points for the 2 downvotes (which were cast before the upvotes) were exceptionally not counted because that would have resulted in a total non-positive reputation for the user.
Your question has been upvoted twice and downvoted twice. The "net votes" on the post is thus 0, making it look like there is no vote at all. Users with the Established User Privilege (1000 reputation) can view vote counts.
So, you gained 20 reputation by 2 upvotes on your post but these were not visible to you because there were also 2 downvotes. ...