Hi Javier,
You were right, the problem lies in one of my plugins.
But bad news, it’s the Woocommerce plugin !
The key you generate is accepted when Woocommerce is disabled.
I am using the latest version of Woocommerce (6.1.1)
It seems that WC has its own lost password system. But I don’t understand why it creates a problem with the standard wp-login.php you use.
I am probably not the only one using Woocommerce and your plugin. Could the problem be caused by a recent WC update ?
Thanks again for your help.
Dominique