Double post to facebook in WP 5.0

I have a plugin at my site. “WP Facebook Auto Publish”
It works fine until I update to WP 5.0 and start using Gutenberg editor.

When I publish a new post at my site, it should automatic publish it at my FB page.
Before I update to WP 5.0 it works fine, only one published every time.

Now when I publish the same post shows up twice, with 1 minutes delay.
I have to go to the FB page and delete the first one.

Any idea why ?

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