pemongillo, PD11 does not support HEVC video, it will import as audio only file and black video. The audio will typically play fine. If you have the iphone set to record HEVC "High Efficiency" video, you might try the "Most Compatible" setting on your iphone which will create a H.264 video instead which is PD11 compatible.
For the HEVC video, if that's what you have, you will need to convert for PD11 to handle properly. HandBrake or many other free utilities are available for that route.
Jeff