[Closed] Translatable option is not working on my website

Background of the issue:
My website primary language is Arabic. English and Syriac as additional languages. When I switch to English or Syriac and access a post that hasn't been translated, I want the whole post revert to Arabic. but in my case its not happening. I have tried various settings in WPML, including 'Translatable only show translated items' and 'Translatable (use translation if available or fallback to default language)', but these did not resolve the issue. I also used the 'Skip language' option in the Language switcher.

Symptoms:
When accessing a post in English or Syriac that hasn't been translated, the header and language direction remain in English instead of reverting to Arabic. Using 'Translatable only show translated items' results in a 404 NOT FOUND error. The 'Translatable (use translation if available or fallback to default language)' option keeps the header in English and the content direction left to right.

Questions:
How can I ensure the header and language direction revert to Arabic for untranslated posts?
Why does the 'Translatable only show translated items' option result in a 404 error?