Gain login access to old CISC AS/400e

Hello all,
i managed to get an ancient AS/400e. It's a german model 9406-300 and in a pretty good condition and seems to be fully working. Installed OS/400 is also in german language. Also got 8 IBM QIC Tapes, which seems to have OS/400 V2, but I think, the installed OS/400 on the AS/400e is newer, as the login says copyright 1996, the QIC tapes 1992.

Except for SRC 0000BBBB, since after that long time, the battery seems to be empty, the IPL is executed and successfully finished. Takes about 30 minutes.

Since I didn't had any console, I managed to get an IBM 3488 InfoWindow II. It's connected to the 6050 Twinax card of the AS/400e. The terminal is configured as id 0 and connteced to the big black Twinax block on port 0. Seems to work fine, as I am getting a login screen for the AS/400e. But I don't know the login credentials. QSECOFR with default password does not work.

But I can access the DST, since the default login works there.
Either by pushing twice option 21 or booting by manual IPL mode.

In DST, I did the following:
1) Choose option 5) working with DST environment
2) Choose option 9) change DST passwords
3) Choose option 4) reset system default password
4) Confirm with enter -> Operating system password override set

After that, I did a complete IPL again. But login with default credentials is still not possible. I am getting CPF1394 as error.

According to the docs, that could mean, that the user is disabled. But from other docs I read, that with main console via Twinax, even a disabled account should be able to login?

I have the suspicion, that maybe my Twinax console is not considered as the primary one? The login screen says, that the display is DSP16. If I press option 65, I get SRC A6005000, which seems to mean, system console is not found? I am not sure, if that is connected to my problem here.

Or does CPF1394 indicate something different? Is there something, I can do more?

Many thanks in advance!
Conrad