Somewhat related: Improvements to the mod-only migrate tool
Mods have the ability to migrate to any site on the Closing > Off-Topic > Migration page using a text box to select a site. This list contains all sites, including child metas. If you type a site name (like "Programmers" or "Code Review"), you'll end up with two sites (the main and their child meta). For examples, you can see "Programmers" and "Programmers Meta". If you accidentally click "Programmers Meta" and then use your backspace key to remove the word "Meta", then immediately click "Vote to Close", the question will still be migrated to Programmers Meta.
To be explicitly clear: In my specific case, the migration text field said "Code Review" as text. However, because I had previously selected Code Review Meta, that ended up being the target. That is a bug and needs to be resolved.
I know because I just did this, accidentally migrating a question to Code Review Meta instead of Code Review. This is not only not intuitive, but I should be able to type a site name for migration. Otherwise, consider just making this field a combo box instead of an editable combo box, especially if the editing function isn't working right.