Trying here to duplicate your scenario
As you can see I put the text and picture next to each other, but that didn't seem to matter............Here's the pic, I chose some blue bunnies. Try it again. You can try it numerous times on the same post and then just delete the post.
Did the pictures upload OK and did you choose & copy the URL under the picture and paste it in the box using the yellow envelope?
Look under Test Forum. The picture uploaded OK and I did copy the URL under the picture and pasted it in the box using the yellow envelope. Still the best I could do is under the Test Forum so far. Otherwise the picture is gigantic if I can't resize it.