Applying Huckel's rule to non-planar compounds
Number 2 is not aromatic because transannular $\ce{C-H}$ interactions cause the molecule to be non-planar although it satisfies $4n+2$. This problem was solved by the synthesis of number 4, which, while a little less than planar but rigid, displays aromatic properties (NMR, etc., Ref 1).
References:

E. Vogel, H. D. Roth, &quot;The Cyclodecapentaene System,&quot; Angew. Chem. Int'l. Ed. 1964, 3(3), 228-229 (DOI:  https://doi.org/10.1002/anie.196402282).