I used spark 2.6.3 to transfer file to another spark 2.6.3 client, but the percentage of file receiver side was shown abnormally and the percentage of transfer side worked well.
After some tests, I found when I used Look&Feel such as Substance Office, it would be shown abnormally.
When I used default Look&Feel, it would work well.
Attached screenshot.
Sincerely,
Frank