UriNormalizer layouts incompatibility

Problem/Motivation

After installing Tome, while saving content I encountered the following exception:

The website encountered an unexpected error. Try again later.

TypeError: strpos(): Argument #1 ($haystack) must be of type string, array given in strpos() (line 55 of modules/contrib/tome/modules/tome_sync/src/Normalizer/UriNormalizer.php).
Drupal\tome_sync\Normalizer\UriNormalizer->normalize() (Line: 152)
Symfony\Component\Serializer\Serializer->normalize() (Line: 37)
Drupal\serialization\Normalizer\ComplexDataNormalizer->normalize() (Line: 23)
Drupal\tome_sync\Normalizer\PathItemNormalizer->normalize() (Line: 23)
Drupal\tome_sync\Normalizer\PathautoItemNormalizer->normalize() (Line: 152)
Symfony\Component\Serializer\Serializer->normalize() (Line: 24)
Drupal\serialization\Normalizer\ListNormalizer->normalize() (Line: 152)
Symfony\Component\Serializer\Serializer->normalize() (Line: 25)
Drupal\serialization\Normalizer\ContentEntityNormalizer->normalize() (Line: 42)
Drupal\tome_sync\Normalizer\ContentEntityNormalizer->normalize() (Line: 51)
Drupal\tome_sync\Normalizer\PathAliasNormalizer->normalize() (Line: 152)
Symfony\Component\Serializer\Serializer->normalize() (Line: 151)
Drupal\tome_sync\Exporter->exportContent() (Line: 20)
tome_sync_entity_insert() (Line: 30)
tome_sync_entity_update()
call_user_func_array() (Line: 355)
Drupal\Core\Extension\ModuleHandler->Drupal\Core\Extension\{closure}() (Line: 307)
Drupal\Core\Extension\ModuleHandler->invokeAllWith() (Line: 354)
Drupal\Core\Extension\ModuleHandler->invokeAll() (Line: 217)
Drupal\Core\Entity\EntityStorageBase->invokeHook() (Line: 900)
Drupal\Core\Entity\ContentEntityStorageBase->invokeHook() (Line: 564)
Drupal\Core\Entity\EntityStorageBase->doPostSave() (Line: 781)
Drupal\Core\Entity\ContentEntityStorageBase->doPostSave() (Line: 489)
Drupal\Core\Entity\EntityStorageBase->save() (Line: 805)
Drupal\Core\Entity\Sql\SqlContentEntityStorage->save() (Line: 354)
Drupal\Core\Entity\EntityBase->save() (Line: 310)
Drupal\entity_reference_revisions\Plugin\Field\FieldType\EntityReferenceRevisionsItem->preSave() (Line: 233)
Drupal\Core\Field\FieldItemList->delegateMethod() (Line: 191)
Drupal\Core\Field\FieldItemList->preSave() (Line: 938)
Drupal\Core\Entity\ContentEntityStorageBase->invokeFieldMethod() (Line: 888)
Drupal\Core\Entity\ContentEntityStorageBase->invokeHook() (Line: 529)
Drupal\Core\Entity\EntityStorageBase->doPreSave() (Line: 753)
Drupal\Core\Entity\ContentEntityStorageBase->doPreSave() (Line: 483)
Drupal\Core\Entity\EntityStorageBase->save() (Line: 805)
Drupal\Core\Entity\Sql\SqlContentEntityStorage->save() (Line: 354)
Drupal\Core\Entity\EntityBase->save() (Line: 281)
Drupal\node\NodeForm->save()
call_user_func_array() (Line: 105)
Drupal\Core\Form\FormSubmitter->executeSubmitHandlers() (Line: 43)
Drupal\Core\Form\FormSubmitter->doSubmitForm() (Line: 589)
Drupal\Core\Form\FormBuilder->processForm() (Line: 321)
Drupal\Core\Form\FormBuilder->buildForm() (Line: 73)
Drupal\Core\Controller\FormController->getContentResult()
call_user_func_array() (Line: 123)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 593)
Drupal\Core\Render\Renderer->executeInRenderContext() (Line: 121)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->wrapControllerExecutionInRenderContext() (Line: 97)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 183)
Symfony\Component\HttpKernel\HttpKernel->handleRaw() (Line: 76)
Symfony\Component\HttpKernel\HttpKernel->handle() (Line: 43)
Drupal\force_password_change\Service\ForcePasswordChangeRedirectMiddleware->handle() (Line: 53)
Drupal\Core\StackMiddleware\Session->handle() (Line: 48)
Drupal\Core\StackMiddleware\KernelPreHandle->handle() (Line: 28)
Drupal\Core\StackMiddleware\ContentLength->handle() (Line: 32)
Drupal\big_pipe\StackMiddleware\ContentLength->handle() (Line: 116)
Drupal\page_cache\StackMiddleware\PageCache->pass() (Line: 90)
Drupal\page_cache\StackMiddleware\PageCache->handle() (Line: 53)
Asm89\Stack\Cors->handle() (Line: 50)
Drupal\ban\BanMiddleware->handle() (Line: 48)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle() (Line: 51)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle() (Line: 36)
Drupal\Core\StackMiddleware\AjaxPageState->handle() (Line: 51)
Drupal\Core\StackMiddleware\StackedHttpKernel->handle() (Line: 709)
Drupal\Core\DrupalKernel->handle() (Line: 19)

Debugging reveals the value to be a configuration array related to layout-paragraphs.

Proposed resolution

Add is_string check to if condition on line 55.