Bash under AIX cursor position error [3]

Use bash download from ibm official site.

Use up key to fand an old command. if you use left key to move the cursor leave the end of the command line, you will not able to move the cursor back to the end of the command line. The cursor will stay over the last char and you are not able to modify the last char any more.

System information:
gdznwh1:/root#which bash
/usr/bin/bash
gdznwh1:/root#ls -l /usr/bin/bash
lrwxrwxrwx 1 root system 27 May 23 09:44 /usr/bin/bash -> ../../opt/freeware/bin/bash
gdznwh1:/dbbackup/archlog#uname -a
AIX gdznwh1 3 5 000D835ED600

XShell version:
Xshell 3.0 (Build 0123) and previsous version

We are currently trying to duplicate your problem. Please give us a few days to test this problem.

Thank you for your understanding.

---
Technical Support

It's very strange that this problem is only appear on my root user.

Even normaly press some command, and press left key some times and right key, the cursor will not go to the end of the command line( stay over the last char).

I don't know if it is the problem of the env params, I will give my env params here:

gdznwh1:/#env
AUTHSTATE=compat
SHELL=/usr/bin/bash
TERM=xterm
LOCPATH=/usr/lib/nls/loc
USER=root
ODMDIR=/etc/objrepos
MAIL=/usr/spool/mail/root
PATH=/usr/bin:/etc:/usr/sbin:/usr/ucb:/usr/bin/X11:/sbin:/usr/java14/jre/bin:/usr/java14/bin:/usr/vac/bin:/usr/vacpp/bin
LOGIN=root
PWD=/
LANG=en_US
TZ=BEIST-8
PS1=gdznwh1:$PWD#
SHLVL=1
HOME=/
LC__FASTMSG=true
MAILMSG=[YOU HAVE NEW MAIL]
LOGNAME=root
_=/usr/bin/env
NLSPATH=/usr/lib/nls/msg/%L/%N:/usr/lib/nls/msg/%L/%N.cat

Finally I found the problem myself.

It is becouse of "set -o vi" cmd.

Sorry for bother you.