Info related to shared post is all `None`

[UlyssesZh]

https://www.facebook.com/LyricaGame/posts/pfbid0ZD1LWTSAtiAbPpem7AA2tpnEh7QXviqY3hf4mfYvg53yoakBb77DEKwqERv8htBzl

When this post is fetched using get_page_info('LyricaGame'), the fields shared_post_id, shared_time, shared_user_id etc are all None.