It seems the vendor's web UI will accept passwords that the RESTful API will not. Specifically, this seems to apply to some special characters.
From the user's point of view, their password will work via the web UI, but not via this client library. They will - quite reasonably - blame the client library for this.
I might guess that the Web UI is modifying the password in some way, perhaps to 'escape' these characters.
If we cannot work out a way to resolve this, then at least we should add as warning to the authentication failed message.
It seems the vendor's web UI will accept passwords that the RESTful API will not. Specifically, this seems to apply to some special characters.
From the user's point of view, their password will work via the web UI, but not via this client library. They will - quite reasonably - blame the client library for this.
I might guess that the Web UI is modifying the password in some way, perhaps to 'escape' these characters.
If we cannot work out a way to resolve this, then at least we should add as warning to the authentication failed message.