There are a couple things to keep in mind here.
Step 1. I wouldn’t do that to your SEO or manipulate your plugin.
– With this concept of changing your site name, it can.. well will affect you SEO.
In short, you should be able to control this information from the Yoast plugin in the Social metabox tab. See screenshot
@ https://take.ms/zE3xf
But maybe that doesn’t work because Yoast still tags on your site name?
– I’m not sure. I don’t use SEO by Yoast. But I would think the above method should work. Have you tried that?
(Implement step 3 either way)
If step 1 doesn’t work you can try the steps below, but would most likely effect your SEO.
Step 2. With what plugins you have you can try some settings like the screenshot below
@ https://take.ms/zZPhzhttps://take.ms/zZPhz
– You will have to zoom in on the screenshot and change those to what you want your site title to be.
(I personally, wouldn’t do step 2, at least not for what you are wanting to do.)
Step 3. Either way, after your changes you will always need to refresh your information to Facebook. Facebook stores cached information about your website that is updated daily (hopefully). After your changes you need to force your new information to show instead of waiting for it to automatically be updated.
– You can do that through their debugger tool @ https://developers.facebook.com/tools/debug/
– This is also where you can “Test” the changes you made until you get them to look right.
– The tool will show you what Facebook sees for your website and will show on Facebook when your post is shared.
Step 4. After you get your content to display how you like, then it would probably be easier if you install this plugin to refresh the Facebook cached/stored information at the page, post level and not have to visit their debugger tool every time, since it sounds like you have quite a bit of articles to refresh for Facebook.
– See plugin > https://www.ads-software.com/plugins/open-graph-rescrape/screenshots/
5. You can always use Easy Social Share Buttons, which should give you more control and power of you socially shared messages, overriding the default Website Tag name.
– See screenshot
@ https://take.ms/Gb0cz
– See plugin > https://codecanyon.net/item/easy-social-share-buttons-for-wordpress/6394476