  An updated analysis of New Physics violating Lepton Flavour Universality, by
using the Standard Model Effective Field Lagrangian with semileptonic dimension
six operators at $\Lambda = 1\,\mathrm{TeV}$ is presented. We perform a global
fit, by discussing the relevance of the mixing in the first generation. We use
for the first time in this context a Montecarlo analysis to extract the
confidence intervals and correlations between observables. Our results show
that machine learning, made jointly with the SHAP values, constitute a suitable
strategy to use in this kind of analysis.
