I think we should start tracking issues that go unresolved and provide a single thread where the community can view the overall success (or failure) of FEC (Flat Earth Conjecture). Granted, I haven't been here very long so I'll be depending on all of you to help fill in the gaps.
As it stands, here are the big issues and their approximate outcomes:
Southern Hemisphere ConstellationsIssue: FE cannot reconcile general positions of stars in the Southern Hemisphere. FE cannot explain observable evidence contrary to what has been established by RE.
Resolved?: No - FES has yet to provide a working (i.e. can be independently verified) explanation regarding the aforementioned issues.
Visible curvature at Lake Pontchartrain CausewayIssue: Visible curvature evident by amateur photographers/videographers showing objects disappearing, bottom first, over a horizon.
Resolved?: No - FES has offered "atmoplanic lensing" as an answer but has yet to provide a working model of how this phenomenon behaves in a manner that is reproducible or predictable.
Location and Movement of the Sun and MoonIssue: FE model for sun and moon movement create multiple contradictions with reality. For clarity, the following:
Specifically, a FE model with the sun never crosses the horizon, it would be impossible for sunlight to illuminate the underside of cloud coverage, and the apparent shape and size of the sun would fluctuate dramatically throughout the day. Most of these contradictions apply to the moon as well.
Resolved?: No. FES has not provided any substantial evidence supporting a position that the sun is the size or distance claimed along with the moon.
NASA ConspiracyIssue: FES claims that NASA is a component of, or central organization responsible for a global conspiracy preventing or restricting travel to Antarctica. Additionally, NASA has also been responsible for a multi-decade long disinformation campaign using cutting-edge photo editing technology, and later, advanced computer-based image and video manipulation to perpetuate the illusion of space travel, a globe-shaped Earth, and numerous other clandestine operations.
Resolved?: No. FES has made multiple, unsubstantiated allegations but has yet to provide evidence that can be corroborated.
GravityIssue: FES contends that gravity does not exist.
Resolved?: No. FES has offered conjecture such as infinite upward acceleration, denpressure, and other responses. To date, none have been sufficient in explaining or predicting phenomena to any measurable degree.
CartographyIssue: No unified map for a flat earth exists that is universally accepted among the FES and explains apparent contradictions with known flight paths commonly used by commercial airlines (i.e., Santiago, Chile to Sydney, Australia).
Resolved?: No. No working map for a flat earth has been offered that reconciles anomalies in landmass size, distances between landmasses, and known non-government travel.
I know there are many others. If you have time, please add what you've come across using the format I've provided above (for consistency). Try not to editorialize.