On our page users are opening posts in a modal (like facebook or twitter).
The links look like this
<a class="showpost" data-mpid="416246" href="/p/416246/">Open Post</a>
We catch the click, execute an ajax call and convert the JSON response to HTML. Even I read that Google can execute ajax for some time now, none of our posts gets indexed. If I make a "fetch-preview" with render in the search console it shows the website correctly with the post opened.
We have more than 500k posts, most of them with very long and good content (reviews of products) and it's really annoying that none of them can be found in search engines.
Any ideas what we are doing wrong?
EDIT: After some days of further research I still can't find the solution. The sitemap status for these links is "Discovered - currently not indexed".
Is it possible that Google renders it correctly but the added content to the DOM is too small to get "noticed"? Its an image, some paragraphs and sometimes comments added to an existing DIV and then we show this DIV with css. Should I hide everything else on the page when opening the post?