Here, I think, you are misunderstanding. I have explain again our issue.
When click on insert into post after I see in visual tab so not add image. also check text tab but not add any type code for image related in text tab.
That means, click on insert into post after go to post but nothing expression.
& also, I was first time fresh install & New latest version using.
Can you please send me your Email ID? so I will sending you Our admin username/password. so You can proper judge. what is issue?
Thanks.