It seems that sometimes using the history of shell commands (arrow up key), scrambled the Output. See Screenshot. This happens here with Linux Mint 19 and sFTP 3.4.7 (on Clientside) and CentOS 8 on Serverside.
A Command in History like
su - zimbra -c "zmgsautil forceSync -a firstname.lastname@example.org -n zimbra"
scrambled the Output (get out there with a clear) and a command like ls -lisah did not scramble.
EDIT 20200714_1023: It seems that there is an Maximum on Chars on each Command until the Cursor return to the first Position.
Edit: 20200714_1026: The same is if you type a long command in the terminal (not only scrolling thru history)