Notice: Undefined variable: selected in warning appearing when filter type is link

Notice: Undefined variable: selected in Drupal\better_exposed_filters\Plugin\views\exposed_form\BetterExposedFilters->exposedFormAlter() (line 794 of modules/contrib/better_exposed_filters/src/Plugin/views/exposed_form/BetterExposedFilters.php).
Drupal\better_exposed_filters\Plugin\views\exposed_form\BetterExposedFilters->exposedFormAlter(Array, Object) (Line: 120)
Drupal\views\Form\ViewsExposedForm->buildForm(Array, Object)
call_user_func_array(Array, Array) (Line: 514)
Drupal\Core\Form\FormBuilder->retrieveForm('views_exposed_form', Object) (Line: 271)
Drupal\Core\Form\FormBuilder->buildForm('views_exposed_form', Object) (Line: 135)
Drupal\views\Plugin\views\exposed_form\ExposedFormPluginBase->renderExposedForm() (Line: 1224)
Drupal\views\ViewExecutable->build() (Line: 390)
Drupal\views\Plugin\views\display\PathPluginBase->execute() (Line: 168)
Drupal\views\Plugin\views\display\Page->execute() (Line: 1616)
Drupal\views\ViewExecutable->executeDisplay('products', Array) (Line: 78)
Drupal\views\Element\View::preRenderViewElement(Array)
call_user_func(Array, Array) (Line: 376)
Drupal\Core\Render\Renderer->doRender(Array, ) (Line: 195)
Drupal\Core\Render\Renderer->render(Array, ) (Line: 226)
Drupal\Core\Render\MainContent\HtmlRenderer->Drupal\Core\Render\MainContent\{closure}() (Line: 574)
Drupal\Core\Render\Renderer->executeInRenderContext(Object, Object) (Line: 227)
Drupal\Core\Render\MainContent\HtmlRenderer->prepare(Array, Object, Object) (Line: 117)
Drupal\Core\Render\MainContent\HtmlRenderer->renderResponse(Array, Object, Object) (Line: 90)
Drupal\Core\EventSubscriber\MainContentViewSubscriber->onViewRenderArray(Object, 'kernel.view', Object) (Line: 111)
Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch('kernel.view', Object) (Line: 149)
Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object, 1) (Line: 64)
Symfony\Component\HttpKernel\HttpKernel->handle(Object, 1, 1) (Line: 57)
Drupal\Core\StackMiddleware\Session->handle(Object, 1, 1) (Line: 47)
Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object, 1, 1) (Line: 99)
Drupal\page_cache\StackMiddleware\PageCache->pass(Object, 1, 1) (Line: 78)
Drupal\page_cache\StackMiddleware\PageCache->handle(Object, 1, 1) (Line: 47)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object, 1, 1) (Line: 50)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object, 1, 1) (Line: 23)
Stack\StackedHttpKernel->handle(Object, 1, 1) (Line: 656)
Drupal\Core\DrupalKernel->handle(Object) (Line: 19)