Have you tried using any redirect plugins?
https://wordpress.org/plugins/redirection/
An example of one is above.
I am having a similar issue with a client site, and the redirect plugins do not seem to work. They appear to ignore the hashbang and just redirect all pages to the homepage of the new site.
I read on the internet that WordPress will ignore the hashbang (#!) – and that another redirect solution needs to be found, but I am having a hard time finding it. Hope someone might have had luck, right now we are losing ranking and people are getting confused since links are no longer working. 🙁
