Error traversing to domain when already logged in

Problem/Motivation

TypeError: strpos(): Argument #1 ($haystack) must be of type string, Drupal\Core\Url given in strpos() (line 358 of /core/lib/Drupal/Component/Utility/UrlHelper.php)

Steps to reproduce

Traverse to a domain where you're already logged in with a different user account.

Proposed resolution

Change domain_traversal > src > Controller > DomainTraversal.php - Line 200 from:

':logout' => Url::fromRoute('user.logout'),

To:

':logout' => Url::fromRoute('user.logout')->toString(),