Thanks Movin, I appreciate you explaining. Actually many people have said things like, “it’s working but not as it was” regarding following the above instructions.
I downloaded the child theme from here: https://colorlibsupport.com/t/activello-child-theme/ I edited CSS to create the site I want and then activated child theme. I then updated Activello and the featured image sizes changed even though child theme was activated. I’m not mistaken that’s what happens. Why? Shouldn’t the child theme stay in tact?
If I upload the child theme when I’m using Activello 1.2.3 then why does it alter when Activello is updated to 1.3.1?
This also happens when I use a plugin to create a child theme from the 1.2.3 version rather than your file.
Can I confirm I can safely operate with an old versions of the theme? So many people advise against this…