Welcome to the forum.
Along with those linked articles, that John T. furnished, can you tell us all about how you are producing the watermarks, the file format, and any Scaling in PrE. The more details, the better.
PS - though I think that one of John's links is to the article linked HERE, there might be some additional info.
And don't forget to render the timeline whenever there's a red line above your clips!
(Press Enter to render.)
When the red lines turn green, you'll have a much clearer preview of what your final output will look like.
Hi all, I got it, when I checked later at the fully rendered
videos they are ok, it's just in the timeline its off and the preview window, but its ok
Great news, and glad that you got your desired quality.