I have upgraded firmware from 220.127.116.11-007R to 18.104.22.168-012R. Yes this happen when pulling tech-dump via tftp or ftp also.
I have checked it via CLI and GUI both, and I am facing same issue. It was not happening in 5.X.
Also I have checked on my test environment, and I am facing issue in that also.
I think there is bug in the latest release.