Why do I get a thick grey color border after I publish my file in a video format?

Greetings, Jordan!

Thank you for sharing your setup in addition to that recording. It was super helpful to see!

I opened the course in Storyline 360, Update 30, where I also see the gray border around 2-7b.MP4 on slide 1.5. So strange! The good news is that you can crop out that distraction with the cropping tool. Here's quick Peek 360 recording of my test and how the video looks after the edit!

In the meantime, this is a great opportunity for our Support Engineers to lend a hand! I opened a case with them where they'll reach out with their findings on what might be causing that by email shortly.

I'll follow along to share any relevant insight here, too!