@chrono79 please start a new support thread and include these 3 things please.
1. The shortcode you are trying to use.
2. An example link to the problem in question.
3. The report from the System Info page of our plugin. Click here if you are unsure how to do this. https://www.slickremix.com/docs/system-info-page/
Even if you have done everything correct your feed could not be showing because you have reached the 200 API limit call per hour. We’ll be making an update next week to actually display this for admins on the Instagram Options page of our plugin so you can know for sure that is the case. In the meantime I would suggest you make sure the cache on the settings->global options page of our plugin is set to 1 day or more. Also using a caching plugin like WP Super Cache is a good idea too. Doing these things will limit the API requests to Instagram and keep your feed alive.