1. Open the attached document (and review the steps from the GIF)
2. Notice the second symbol's boundaries are giant (although the registration point is displayed within the artboard), and the Symbols panel seemingly shows nothing in its thumb
3. Double click the second symbol to edit it
4. The symbol opens and jumps into the middle of its giant boundaries, and the registration point moves as well
5. Exit the mode
6. The symbol is now displayed in its intended place, has normal boundaries, has the registration point in the same place, has a normal thumb...
7. ...but if you make other changes in a doc, save and reopen it — you’d get the the same exact problem as before.

The appearance of the document is broken, and exporting it give wrong results. This is a very dangerous problem and leads to errors and money loss.