In this build failure, the S2 cap near the pole gives a bound covering it, but 2d index interprets it literally to the following box, whose longitudes should be (179.005 -->> -110.896) instead, on the other side of the earth.
The other failure of nearSphere seems the same problem as it is also very close to the pole. For nearSphere we expands the search area though. We should deprecate the support of spherical queries on 2d index and prohibit them in the future.
As a workaround, spherical queries using 2dsphere index work as expected.