  Fe3GeTe2 (FGT), a ferromagnetic van der Waals topological nodal line
semimetal, has recently been studied. Using first-principles calculations and
symmetry analysis, we investigate the effect of a uniaxial tensile strain on
the nodal line and the resultant intrinsic anomalous Hall effect (AHE). Our
results reveal their robustness to the in-plane strain. Moreover, the intrinsic
AHE remains robust even for artificial adjustment of the atomic positions
introduced to break the crystalline symmetries of FGT. When the spin-orbit
coupling is absent, the nodal line degeneracy remains intact as long as the
inversion symmetry or the two-fold screw symmetry is maintained, which reveal
that the nodal line may emerge much more easily than previously predicted. This
strong robustness is surprising and disagrees with the previous experimental
report [Y. Wang et al., Adv. Mater. 32, 2004533 (2020)], which reports that a
uniaxial strain of less than 1 % of the in-plane lattice constant can double
the anomalous Hall resistance. This discrepancy implies that the present
understanding of the AHE in FGT is incomplete. The possible origins of this
discrepancy are discussed.
