You can see by the glow that there are 2 portals at the same place.
Standing over the 2 portals (and thus activating the topmost one) brings me near to this weird location at payon:
As far as I can remember, there was no portal there. Also, the portal range is 5, which is too large for it, so if you step at 190, 64, 2 cells below the expected range, you are warped to pay_fild08.
The correct portal to pay_fild08 still exists:
