Here’s a quick tip on how to manually centered your image caption when WordPress “align” attributes with caption shortcode doesn’t seems to work.
Maybe it’s your WordPress installations or your theme that’s causing the caption aligning to fail and you really don’t have the time to look for the root cause of that problem.
I’ll show you the solution (I discovered) on how to fix that quickly by using the <center> tags.
You can do this using two methods:
1- Image insert – when you add an image using the Add Media button in your post editor, you will see a caption box textarea on your right side of the Insert Image pop-up box screen. Just type <center>Your Image Caption</center> and upload the image using the Insert into post button. (refer image below)
2- Edit Image – if you wish to edit your image caption using the Edit button (a small pencil icon when you click the image), you can edit/update your image caption by just typing <center>Your Image Caption</center> and then press Update button inside the Image Details pop-up box screen. (refer image below)