It's tough to understand what you see unless you supply the project, so others can take a look. Try applying the Letterbox to Aspect Ratio effect to the video.
The process is easy, quick and can be done privately. Just follow these steps...
Back up --- With your project on the timeline, click on MENU at the top-left. Click FILE|BACK UP PROJECT FILES TO FOLDER. Choose a folder and SELECT FOLDER.
Zip the folder --- It will be numbered. In Windows right-click on it and Send To > Compressed (zipped) folder.
Upload --- Use a free server - Google Drive, MS OneDrive, etc.* - to upload the zipped folder. When it completes...
Get link --- Right-click the file and click SHARE. If using Google, right-click the file, click SHARE | SHARE. Change "restricted" to "anyone ... can view"
Share --- Click COPY LINK or OK | DONE. Paste that link here, or click the folder at the top-right of this forum to message it privately. It won't be shared.
* Before uploading, right-click the folder, click PROPERTIES. Look at the File Size to confirm that it's not too big for the free space on the server.