One year after :)
I am using both Vantage Premium and Sydney (free.) and I have (almost) the same issue. In particular when I add the price table widget to otherwise well behaving pagebuilder-ed post.
ps: I have to say I do not understand fully this “TinyMCE issue”, is this not a default/mandatory WP editor component?
(my premium purchase code available on request)
offending post is here http://ability.dbjdbj.org/t2/2015/12/07/chronos-ldc/
kind regards …
ps: sorry for noticing too late the remark about new thread recommendation