On this post, I'll be showing you the solutions to post image thumbnail not showing on your site/blog homepage. There are two solutions to this issue. The first solutions will definitely solve your problem while the second solution must surely solve the problem.

Method 1.
Go back to the post editor and click on the "html" post editor which is located at the top left corner.
Look for the part which contains the html code for the image you upload (usually the first image, if you uploaded more than one image in the post)
Locate the link where the image is sourced from and change src="https:// to src="http:// (I simply removed the "s" from the first one) and also try doing the same to every link address located in the image html alone and update the post. This should work, but if it doesn't then method must surely work

Method 2...continue here»»https://www.dominzyloaded.com/2020/04/solution-to-blogger-post-image.html?m=1