Hello,
This is not the theme issue this is related to those social platforms. Most of them have different settings.
You can check the below screenshot when I shared you site link on skype it shows your logo:
https://jmp.sh/oSQ5QL0
If you’re using Yoast WordPress SEO, you have a built-in setting for Facebook images. Under your SEO > Social menu, go to the Facebook tab and select an image under “Frontpage settings.” You can also set an image as a fallback, for posts that have no featured image, under “Default settings.”
Other SEO plugins may have similar capabilities.
Best Regards.
.
