DB2+MQ+Docker, enable_MQFunctions, Password validation failed

It’s continuation from this post.
I still have problem with settings my user’s password after executing enable_MQFunctions
db2diag.log shows this:

2019-05-27- I176069E471           LEVEL: Warning
PID     : 980                  TID : 139754553206528 PROC : db2sysc
INSTANCE: db2inst1             NODE : 000            DB   : DB2INST1
APPHDL  : 0-7
HOSTNAME: d9a35edd3e4d
EDUID   : 18                   EDUNAME: db2agent (DB2INST1)
FUNCTION: DB2 UDB, bsu security, sqlexLogPluginMessage, probe:20
DATA #1 : String with size, 67 bytes
Password validation for user db2isnt1 failed with rc = -2146498587

I changed my password (for db2inst1) using passwd in terminal after build. And during docker build I even used: RUN echo "db2inst1:passw0rd" | chpasswd
Terminal recongnize my password but enable_MQFunctions does not.

Source: StackOverflow