Hi,
we aware of this problem, since we respect the aspect ratio of the original clip. This problem happens when applying Position effect to move the logo.
Effects are applied only within the original clip, this became a problem if output aspect ratio is different.
We are working on solve this problem. For now, the work around would be manually convert the aspect ratio (before position effect) to output aspect ratio by applying aspect ratio transform effects.
Thanks for reporting issues and sorry for the inconvenient.