Frequent "Should have \sum_n W_nk = 1" errors in analysis

[tlhr]

I've noticed that for some systems legs fail due to:

ParameterError: Warning: Should have \sum_n W_nk = 1.  Actual column sum for state 0 was 0.990260. 15 other columns have similar problems

This example was an RBFE solvent leg running for 10 ns with 15 lambda windows, so I would have expected adequate sampling. Could it be related to this PyMBAR issue? My analysis succeeds when I force an update to PyMBAR 4.0.3 and modify MultistateEquilFEAnalysis to pass analysis_kwargs={"solver_protocol": "robust"} to MultiStateSamplerAnalyzer as suggested in the last comment. Maybe this could be made the default? I guess this is also related to #443.