iMovie library transferred to external hard drive reopened video no sound

Hello I’m hoping I can get some help. I purchased a 2tb WD external hard drive, I formatted it to exFat ( to be able to use from MAC to Windows) the steps I took were.

• I closed iMovie and opened the movie “iMovie folder” then transferred it to my external hard drive after formatting to exFat.

• Once all the files were transferred which was about 1.5 I went to check to see if audio and video appeared however the audio was not there I have not deleted off my computer but no audio .

1st question is did I transfer wrong?

2. Did I corrupt the movies?

3. They had audio before so I am not sure what I did.

4. Do I need to delete the render file before transferring could this affect audio?

5. I changed the permissions to read & write for myself and staff area and everyone is only allowing for read.

6. I have not deleted it from my iMovie but did notice that when I did the transfer sound is gone but it shows the file of whatever music I used is there.

• I’ve looked up every YT video walk through and did them. What am I doing wrong?

• ALSO, there is no audio for QuickTime either.

** SIDE NOTE : I was just thinking as well if I have to do the format to the WD external hard drive to APFS or Mac OS Extended (Journalled)? Maybe I can’t use exFat?