Unable to use updated openstack credentials

Juju version: 2.9.32
Cloud: Openstack

I'm hitting an issue with authentication after updating an openstack user credential.
These are the (redacted) credentials in use:

  ```
  juju show-credentials --controller prodstack-is-beta prodstack5 stg-jsimpso-test --show-secrets
  controller-credentials:
    prodstack5:
      stg-jsimpso-test:
        content:
          auth-type: userpass
          validity-check: valid
          domain-name: ""
          password: <redacted>
          project-domain-name: Default
          tenant-id: stg-jsimpso-test_project
          tenant-name: stg-jsimpso-test_project
          user-domain-name: Default
          username: stg-jsimpso-test
          version: "3"
        models:
          stg-jsimpso-test: admin
  ```

That's the only credential present for that model:

  ```
  juju show-model stg-jsimpso-test | yq eval '.stg-jsimpso-test.credential'
  name: stg-jsimpso-test
  owner: admin
  cloud: prodstack5
  validity-check: valid
  ```

In that state, the model is able to deploy machines with no problem.
If I then update the openstack user's password (e.g.):

  `openstack user set --password example1 stg-jsimpso-test --domain default`

Unsurprisingly, the model is unable to deploy a new application:

  ```
  juju deploy ubuntu
  Located charm "ubuntu" in charm-hub, revision 21
  Deploying "ubuntu" from charm-hub charm "ubuntu", revision 21 in channel stable on focal
  ERROR cannot add application "ubuntu": failed to get list of flavour details
  caused by: authentication failed
  caused by: requesting token: Unauthorised URL https://<keystone_url>:5000/v3/auth/tokens
  caused by: request (https://<keystone_url>:5000/v3/auth/tokens) returned unexpected status: 401; error info: Failed: 401 error: The request you have made requires authentication.
  ```

This also happens when I try to "juju show-model":

  ```
  stg-jsimpso-test@is-bastion-ps5:~$ juju show-model
  {}
  ERROR accessing model environment: creating environ for model "stg-jsimpso-test" (f448c790-d617-407e-86f4-1b3808e3d803): authentication failed.: authentication failed
  caused by: requesting token: Unauthorised URL https://<keystone_url>:5000/v3/auth/tokens
  caused by: request (https://<keystone_url>:5000/v3/auth/tokens) returned unexpected status: 401; error info: Failed: 401 error: The request you have made requires authentication.
  ```

So I update the credentials and verify nothing has changed except the password:

  ```
  juju update-credential --controller prodstack-is-beta prodstack5 stg-jsimpso-test -f mine.yaml
  juju show-credentials --controller prodstack-is-beta prodstack5 stg-jsimpso-test --show-secrets
  controller-credentials:
    prodstack5:
      stg-jsimpso-test:
        content:
          auth-type: userpass
          validity-check: valid
          domain-name: ""
          password: example1
          project-domain-name: Default
          tenant-id: stg-jsimpso-test_project
          tenant-name: stg-jsimpso-test_project
          user-domain-name: Default
          username: stg-jsimpso-test
          version: "3"
        models:
          stg-jsimpso-test: admin
  ```

After that, I can "juju show-model" as expected:

  ```
  stg-jsimpso-test@is-bastion-ps5:~$ juju show-model
  stg-jsimpso-test:
    name: admin/stg-jsimpso-test
    short-name: stg-jsimpso-test
  ```

But I can't deploy new applications:

  ```
  stg-jsimpso-test@is-bastion-ps5:~$ juju deploy ubuntu
  Located charm "ubuntu" in charm-hub, revision 21
  Deploying "ubuntu" from charm-hub charm "ubuntu", revision 21 in channel stable on focal
  ERROR cannot add application "ubuntu": failed to get list of flavour details
  caused by: authentication failed
  caused by: requesting token: Unauthorised URL https://<keystone_url>:5000/v3/auth/tokens
  caused by: request (https://<keystone_url>:5000/v3/auth/tokens) returned unexpected status: 401; error info: Failed: 401 error: The request you have made requires authentication.
  ```
The credentials themselves work fine in other regards:

  ```
  echo $OS_PASSWORD
  example1

  openstack flavor list -c Name | head -n 4
  +-------------------------+
  | Name |
  +-------------------------+
  | stag-cpu4-ram4-disk100 |

  ```

It's also worth noting that if I reset the openstack password back to what it was originally & update the juju credentials accordingly, everything starts to work again.