perhaps the distinction between multivariate and univariate as defined in the docs is not clear to me:

Univariate / Multivariate: A multivariate model explicitly models the interactions between multiple time series in a dataset and will provide predictions for multiple time series concurrently. In contrast, a univariate model trained on multiple time series implicitly models interactions between multiple time series and provides predictions for single time series concurrently. Multivariate models are typically computationally expensive and empirically do not necessarily offer better forecasting performance compared to using a univariate model.