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Attached files: Capture-addCommentBox.PNG
Yeah, that's not exactly how it's supposed to look. Something is throwing off the styling of the button, and I suspect it is due to a css class or style conflict. Can you temporarily check with another theme (preferably the default WP theme) just to see if it looks correct? That will help us get closer to a solution. Thanks!
Thanks for your response.
1. With "Twenty Nineteen" enabled I get a "Fatal Error" on the front page and on the post page. Image attached.
2. I use an Extra Child Theme (Extra from Elegant Themes). With the regular Extra theme it looks problematic like it does now. When I switch to DIVI (Elegant), it's better, the way it's supposed to be I suppose. Image attached.
(Also, it seems that when I activate a different theme and try to use Highlighter on a post it changes the structure of the post - increases the margins quite a bit. That's happened twice. Doesn't look bad, but it's not what I wanted or expected. Image attached.)
Attached files: Capture_2019_front page Fatal error.PNG Capture_Divi_InlineBox-LooksBetter.PNG Capture_margins increased.PNG
The fatal error when twenty nineteen is installed is coming from something within the divi page builder. Try also temporarily disabling all of your plugins except highlighter pro when you switch to the default theme - just for testing purposes (if you still want to test this).
But as for the margins I think it's a style or class conflict issue - if I could look directly at that URL from your screenshot I could determine the cause of this.