I have had this happen to me multiple times over the course of the ‘Super Adventure Box’ event and it is utterly infuriating.
When running out of lives and going to the room where you can continue by giving Moto a continue coin there is a chance that the camera (and possibly the player character) starts shaking violently and then place the player character in one of the corners of the room, utterly unable to talk with Moto.
This has happened to me twice during a tribulation, one of which was rather close to the end as well which was incredibly frustrating.
The only way I can see to fix this is: When you die with your last life (life 0) and you have a bomb equiped you can unequip the bomb in the Game Over room and it allows you to move freely around the room which makes it possible to talk with Moto again.
Hope this post will serve some use even if it is near the end of the Super Adventure Box event.