Ancient City Missing Center

This ancient city spawned without a center.

I have been tracking this ancient city for hundreds of blocks and when I finally got to the entrance, the staircase at the end leads to what looks like a chunk border where the chunk is solid blocks. I see a castle wall to the left of the entrance, but is cut off by this chunk also.

Everything I have seen about ancient cities show this massive open area where the center is clearly visible with a night vision potion. All I see is a massive chunk of blocks. I tried plowing through the blocks and it doesn't lead anywhere. I have mined for 250+ blocks in every direction from this staircase and it doesn't lead anywhere but to some caves (normal and deep dark caves).

Definitely a bummer.. I was excited to finally find one in survival mode.