  In this addendum to arXiv:1811.09603 we update our results including the
recent measurement of ${\cal R}(D)$ and ${\cal R}(D^*)$ by the Belle
collaboration: ${\cal R}(D)_{\rm Belle} = 0.307\pm0.037\pm0.016$ and ${\cal
R}(D^*)_{\rm Belle}=0.283\pm0.018\pm0.014$, resulting in the new HFLAV fit
result ${\cal R}(D) = {0.340\pm0.027 \pm 0.013}$, ${\cal R}(D^*) =
{0.295\pm0.011 \pm 0.008 }$, exhibiting a $3.1\,\sigma$ tension with the
Standard Model. We present the new fit results and update all figures,
including the relevant new collider constraints. The updated prediction for
${\cal R}(\Lambda_c)$ from our sum rule reads ${\cal R}(\Lambda_c)=
\mathcal{R}_{\rm SM}(\Lambda_c) \left( 1.15 \pm 0.04 \right) = 0.38 \pm 0.01
\pm 0.01$. We also comment on theoretical predictions for the fragmentation
function $f_c$ of $b\to B_c$ and their implication on the constraint from
$B_{u/c}\to\tau\nu$ data.
