I would have solved, in this way, at least as regards the portfolio.
I hope that the setting of the plugin that I run the portfolio, do not adversely affect the operation of the plugin with other pages or options.
Polylang settings:
Options ON
Portfolio Items ON
Portfolio Category ON
All other synchronization options OFF
Create versions in the second language only with + button, do not use plugin that clones post or page: this applies to 'page portfolio', 'portfolio items' and 'category portfolio'.