  Na3Bi is a Dirac semimetal with protected nodes that may be sensitive to the
breaking of time-reversal invariance in a magnetic field B. We report
experiments which reveal that both the conductivity and resistivity tensors
exhibit robust anomalies in B. The resistivity $\rho_{xx}$ is B-linear up to 35
T, while the Hall angle exhibits an unusual profile approaching a
step-function. The conductivities $\sigma_{xx}$ and $\sigma_{xy}$ share
identical power-law dependences at large B. We propose that these significant
deviations from conventional transport result from an unusual sensitivity of
the transport lifetime to B. Comparison with Cd3As2 is made.
