@pfefferle After testing many, most generating various problems, incl. with AP, I settled with:
- WP Fastest Cache (page cache)
- Docket Cache (persistent object cache)
So far have had no problems posting via AP, receiving AP comments or webmentions, etc. on 2 different blogs.
I'll reactivate both plugins and check if it still works.
But, big Q, when they're active, other Friendica users (at least) might never be able to connect...