If the video and audio is out of sync after exporting, please follow these steps to have a check.
1.Reload the project (.wve) file to Filmora，check if all the elements on timeline have been aligned precisely.
2.Go to Media library, select the original video of the project, right click and select Properties,it will show you the basic info, such as resolution, frame rate and bit rate.
3.Go to the output video, select settings and refer to the properties info to adjust the output parameters as the same or similar as the orginal video.If you can not find the value in the dropdown list, you can also input the customized value manually.If it did not help, please open the project, select Archive project under File and it will be saved as a .zip folder, please send the folder to us for analysis. You can attach it directly if the file is less than 20M. For file larger than it, please refer to web https://www.wetransfer.com/ to transfer it. And please keep me posted by the email address:email@example.com.