I've noticed two other weird side-effects of this bug (or perhaps other bugs):
1) The first child post does not get a text slug; the post number is used as the slug
2) Child post titles have a space added before them
1) The first child post does not get a text slug; the post number is used as the slug
2) Child post titles have a space added before them
Again, the resolution for now seems to be to downgrade to Types 1.1.x but that's not a long-term solution!