Peter,
I just tested on your site. At first, I left a review and it posted to my Activity Log / Timeline, as expected. I then:
* Deleted that post from my Timeline
* Went into the Joomla admin area and deleted my review.
* I then published the Open Graph - jReviews plugin.
* Then, I reviewed the same listing again.
The review properly posted to my Timeline as expected, the same as when the plugin was disabled. I even left a review on a different listing and it too posted to my Timeline.
Can you test and see if you're still not able to post? If not, please give me some more steps as to what you are doing so we can test more closely to what your trying (the exact listing, any settings you change, etc).
I deleted my 2 reviews. However, I left your site in the same state as my last test, so you can see the configuration that I was able to successfully post with> Again, the only change was to enable the Open Graph - jReviews plugin.
Thanks,
Alex