Thank you for your post.
I am unable to replicate the issue. This is what I have done:
1. In FileMaker Pro 15.0.2, I created a Container field "Container".
2. In Layout Mode, I set the field for Interactive content.
3. I gave the Container field the object name "Media".
4. In Browse Mode, I inserted a mp4 video file (1:41 in length).
5. In Script Workspace, I created a script "TEST" that executes the step:
AVPlayer Play [ Object Name: "Media" ; Presentation: Start Embedded ; Position: 13 ]
6. I set the file for Network Sharing.
7. I launched FileMaker Go 15 from an iPad.
8. I opened the hosted file.
9. I tapped the left arrow, tapped Scripts, and tapped "TEST".
The video started playing embedded in the Container field starting at the 0:13 mark.
Let me know what I am doing differently than you so I can reproduce the issue.
Many thanks, TSGal. This matches what I had. However, I had inadvertently ticked the 'Start playback automatically' option for the container field. Clearly this must override any AVPlayer commands.