Steps to reproduce the issue

Tab Images: Append Caption-Text for Teaser Image:

Expected result

Caption-Text is shown near Image.

Actual result

Text is shown if you hover the Image, so its a Title.

System information

Joomla! 3.7.0-rc1
macOS Sierra, 10.12.3
Firefox 52.0 (64-bit)

MAMP 4.1.1

• PHP 7.0.15
• MySQLi 5.6.35