Our Discourse is unable to generate preview for our domain, even as I’ve made sure that our OpenGraph tags are valid and in fact shows up in iframely as recommended by some other posts in this forum.
@Falco I have fixed the issue, so now the previews do get displayed.
However, anything that was previously deemed “unpreviewable” doesn’t seem to show up anymore. It appears that Discourse has saved URLs that it cannot fetch with HEAD previously in some type of cache (this is just me guessing). What can I do to invalidate that data and make it try to fetch previews of all URLs?