Was testing some things out and set the show duration to 2 minutes. When two minutes came around it didn't change. I'm I missing something or miss understand how it works?

Was testing some things out and set the show duration to 2 minutes. When two minutes came around it didn't change.

The Show Duration setting, is More like a Minimum Duration.
Each Clip has a Length that it lasts for.
A single Card May have a total of 30 minutes, but that is divided up into multiple clips.
The Total length of all Clips combined is where the Shows Time comes from.


Example:
When a card is Played, it is played clip by clip.
The 1st clip might be 28 seconds long.
Then the 2nd clip is 62 seconds, So far 90 seconds have been played.
Then a 3rd clip might start and it is 1 minute and 23 seconds.

Since you had the duration set to 2 minutes or 120 seconds.
The 1st Two clips combined did not exceed 120 seconds, combined they were only 90 seconds.
So it played a 3rd clip, but this clip is 83 seconds, and when added to the 90 seconds will make a total of 173 seconds.

The 3rd clip will play to completion, and this total time now exceeds our 2 Minute duration, so Then a New card will be selected.

The Show doesn't stop in the Middle of a clip, the full clip being played will play to completion.

Hope that Helps.