APM change AD password failed (1523862124)

Hello,

I'm trying to implement a small change AD password page on F5 APM, simple HTTPS virtual server with access policy, as described on Internet : - logon page step 3 on checkbox, both post and session variable on change_password - AD Auth to my AD AAA pool.

I get to the logon page, the user is authenticated, only the password change itself does fail :

AD module: authenticate with 'test@DOMAIN.LOCAL' successfully

AD module: change password for 'test' failed: (1523862124)

AD module: (): (1523862124)

AD agent: Auth (logon attempt:0): failed to change password for 'test'

Anyone an idea ? Must again be something obvious but after several hours spent on the issue I still don't get it... And I'd like to have sorted out before my holidays tomorrow night :-)

Thanks !

Gerald