Premiere Elements 2019 Project Settings

Bob,

I would certainly agree that a 1080 project with 1080 media output to 4K would not be good work.  But, 4K output to 4K does. 

I tested it by forcing the setting of a project to 1080p60 and loading a few 4K clips.  The orange render bar lit up.  Edit rendering worked.  Then I used default 4K output settings.  There was no visual loss of quality.  There is every appearnce that output rendering reads directly from the source files, not the project files.  (I can send you some 4K files if you don't have them and want to try it.) 

This is an old thread, but might help:

https://community.adobe.com/t5/premiere-elements/help-changing-project-settings-of-existing-project/m-p/9706868

There is no way to change project settings in Premiere Elements after the project is started.  Normally they would be set automatically and correctly when you put the first clip on the timeline.  There is also a way to force settings at the beginning of a project.  

All may not be lost!  Project settings are most important during editing.  If they don't match the media, editing can be rough because the computer has to work so hard to convert the media to the project.   At output the coding, rendering or transcoding (whatever you want to call output!) is done by re-reading the source media from scratch, frame by frame and putting it into a format you specify.  

In other words, before you start over, try exporting out a finished video to whatever final specs you want.  It probably will work.