@gonzalo-cavanagh this is a known issue:
https://github.com/mementum/backtrader/pull/418

It's not yet merged unfortunately, but you may try to apply this fix locally and see if it solves your problem.

Alternatively you may try to downgrade the matplot package to 3.2.2.

The following post discussed this issue:
https://community.backtrader.com/topic/981/importerror-cannot-import-name-min_per_hour-when-trying-to-plot/4