It appears that the files that I tried to restore from S3 were corrupted and/or damaged. I am backing up the files again. I believe that the problem is solved. I appreciate the help....

I will try a clean restore and then try to combine as you suggested

I did not make this clear, but I used the Restore Plan. I only used the Cloudberry Explorer to verify the size of the original backed up file.

Using Ultimate edition

From the Cloudberry Explorer (S3)
“Avatar.mkv 32.2 GB 1/24/2021 7:26.22 PM File Standard”

The resulting restores on my desktop
Avatar.mkv.part_1 9/2/21021 10:09 AM Type: PART_1 File 6,761,153 KB
Avatar.mkv.part_2 9/2/21021 11:09 AM Type: PART_2 File 6,761,153 KB
Avatar.mkv.part_3 9/2/21021 08:42 AM Type: PART_3 File 6,761,153 KB
Avatar.mkv.part_4 9/2/21021 08:42 AM Type: PART_4 File 6,761,153 KB
Avatar.mkv.part_5 9/2/21021 08:42 AM Type: PART_5 File 6,761,153 KB

• Chunk Size 10 MB
• Thread count 6
• Process Priority Normal
• Memory Automatic
• Unlimited disk usage

Single file restore plan:
• Restore from latest version
• Selected the video from the S3 cloud
• Set the restore location on my desktop
• Ran the restore plan

I must be doing something wrong (or something stupid)