I think, I’ve found the reason why it doesn’t work.
In the settings of the plugin I wasn’t saving card data on stripe (the corresponding checkbox “Do not save card data on Stripe” was checked).
In version 2.0.37 this didn’t prevent the plugin from working perfectly. But in version 2.0.38 it does! This checkbox must remain unchecked.
Perhaps this setting isn’t necessary anymore. Is it?
Anyway, I would like to thank both of you, @mra13 and @alexanderfoxc, for having looked at my problem so quickly. I appreciate.