Today I sent out my first MailerLite email regarding a new blog post after I changed my theme to Soledad.  Unfortunately, it did not include the featured image.  When I sent those emails out using my old theme, the featured image was there.  

There is a plugin which I have installed that corrects this problem.  I don't care much for continually adding in plugins to solve problems.  Is there a way to work around this with CSS?  

Thanks in advance for your assistance.

Steve