As yours is a lengthy video perhaps you can upload just the 4K portion that's not exporting correctly.
Place it on the timeline, then click FILE|SAVE AS PORTABLE PROJECT. If there are a large number of files, Zip them.
In Windows, select (highlight) all the files, then right-click on one of them and SEND TO|COMPRESSED (zipped) FOLDER.
Upload the result to any free server, such as Microsoft OneDrive, Google Drive or the like. You may have to create an account.
Once uploaded, share the file publicly. With OneDrive, simply right-click on the uploaded file and then click the SHARE choice.
Paste the shared link here, and someone will check it out.
Before you go to this trouble, please download and install the latest VP version, and try your export once again.