Loking at the tunnel in NRo going to commonlands, there are several breaks in the mesh, first at the mouth of the tunnel, another near the CL zoneline. Both of them have 2way links to bridge them. The CL end is weird, because from the NRo side, it is just a break, coming from CL there is a wall there blocking the tunnel. The link goes through it, but maybe that wall is causing the problem.
Pretty sure the North Ro(B) zone is the current file - North Ro(A) actually includes the Large room where the LDON camp, Commonlands tunnel, etc. are located, which would move the area where all the auctions, etc are on early TLPs to North RO - the tunnel in that zone file runs all the way to the Commonlands Mouth of the tunnel. B is the one with the wall and breaks, that tunnel is only the first part of the tunnel, and leaves the merchant area in commonlands.