It's not a bug for me, it's like Vegas works. The preview window does not automatically sync to the keyframes of the Media FX. If I need it, I used HOS to find the keyframe positions in preview and then apply it to the Media FX. I do it so in the video stabilization, if I use it at the media level.
Just a guess, but it could be because media effects are able to be applied to the clip while still in the project media pool, before it is on the timeline and therefore before where it is or if it is on the timeline is considered. That may be why it does not allow for auto-sync to where it is on the timeline. Event level and beyond effects must be on the timeline to be applied, so syncing it to a position on the timeline doesn't cause a conflict when it doesn't find a timeline to sync it to.
wrote on 9/30/2019, 5:52 PM
For information only, a temporary workaround until this bug is fixed: You can see the FX's controls in preview window by clicking on an empty area of the timeline.
This issue dates back at least to VP12. I tested with the Cookie Cutter FX etc..
I believe the VEGAS team use the term "video preview interacts" for these on-screen controls.
I see no fundamental reason that the video preview interacts should not display for media FX. As demonstrated above, they display for media FX when the cursor is over an empty area of the timeline, so why not when it is over the event?