Negative voltage on output of an OP249 stage

Hello there,

hope this is the right section (I thought maybe the IC amp area would also work).

I have built my first prototype on an double stage phono pre (double LT1007 for MC / OPA 2604 for MM and OP249 as 2nd stage), following an existing design from the German analog-forum.

I built the schematics in Eagle and created a PCB from it (so I know that the board matches the schematics).
Unfortunately, I just got a bug hum when I tested on MC, with a slight and very distorted idea of music.
So I checked everything with an oscilloscope, and while the MC and MM stage looks good, the 2nd Stage shows a very wired behaviour.
Even if the Jumper between the stages is open and all other ICs are removed, the OP249 got -12,6V DC on both output pins (1&7).
When I measure the socket, without the OP249, there is no voltage on the pins.

Power supply looks good (+14,8V on pin 8 and -14,8V on pin 4), and I can not measure any strange connection from any of the pins, all looks good.

Another thing that is strange: I pulled the input pins (3 & 5) to GND to ensure that I do not amplify any strange input.
While one output pin (7) stays at -12,6DC, the other one (1) went to +14,3V DC.

I already swapped the OP249 to another one, but it shows the same behaviour.

Any idea, where I should look?
Here is the schematics of the stage /don’t mind the wired dots, they are just for multi-raster for the foil caps):

Thank you already and with kind regards,