This should not actually be an error - according to the FAQ, two of the criteria which prevent a question from counting on your accept rate are "Being closed" and "Having no answers". Your migrated question satisfies both of those, so it does not count.
Furthermore, of 14 questions asked you have only 11 eligible for accept rate (of which 9 are accepted - you can see this by hovering over your accept rate if you didn't already know). You have 1 question asked within 4 days that doesn't count, and 2 closed questions (including the migrated one). So that subtracts from 14 to yield the 11 questions remaining - the migrated one isn't counted.
...though fully reviewing your profile, you have 12 questions with accepted answers... so I'm not quite sure what is going on. But the migrated question should not be part of the calculation.
In the future, for a general scenario with migration stubs, as Bill the Lizard (theoretically might have) said, "The best course of action is to flag it for deletion". A migration stub is locked, so the only people who can actually affect it are the moderators. So to get the people who actually have power on the relevant site, the best course of action is to flag it for moderator attention.
As random has now deleted your migrated post, your accept rate is still at 82% with 9 out of 11 eligible. Which means that the migrated post was not the reason your accept rate is below 100%. It is an error in the update of the display, not the presence of a migrated question.