Random Error: Call to undefined method Drupal\menu_link_content\Plugin\Menu\MenuLinkContent::getLanguage()

I'm having a Problem where I have difficulties to get to the bottom of it.

After a deploying process, which ends with a "drush cr" I see randomly fails, where i get this error on a page call:
"Error: Call to undefined method Drupal\menu_link_content\Plugin\Menu\MenuLinkContent::getLanguage() in Drupal\menu_multilingual\Menu\MenuMultilingualLinkTreeModifier->isTranslatedMenuLinkContentMultilingual() (line 263 of modules/contrib/menu_multilingual/src/Menu/MenuMultilingualLinkTreeModifier.php)."

After another cache-clear, this disappers, until maybe the next time. I don't find a pattern. Sometimes every page is available after deploying, sometimes one page has this issue. And not always the same page.

Once I had the chance to get this in my local envoirenment, and saw the error while checking an untranslated menu-item, which is an instance of "MenuLinkContent". Every other menu-item before is an instance of "MenuLinkContentMultilingual" (they are translated).

I added a workaround with "method_exists($link, 'getLanguage')" before line 263 of modules/contrib/menu_multilingual/src/Menu/MenuMultilingualLinkTreeModifier.php, to avoid this from happening. But i can't figure out why the method is not available, only after a cache rebuild.

Anyone a idea what may be the cause of this?