I tested it in Joomla 2.5
I used it in an article adding the plugin.
The settings were:
Player Type: HTML5
When I opened the page the video started playing auto - without clicking in Play.
The player is embedded as an orth to me.
We have support forum:
Please post your message there.
Also the link to your website ans screen-shot of gallery settings are required. You may send it to us vie contact form on our website: http://www.extensions.compass.com.pa/