I have a technical question which i have been trying to solve on my
own without success:

I would like to have a specific image for the web preview whenever I
post my website on Social Media. I changed the image via Layout & SEO
with the Meta Tags, but I am still getting another image from my
website.

I then tried installing Yoast SEO and changed it from there but it
still doesn't work. What do you think could be the problem?

(see screenshots attached)