special episode not showing in "next up"

[chenks]

update
if i enable the setting "Display specials within their series they aired in" then this special episode appears in the "next up", however that setting also means that the special is listed as an episode within season 18, which it isn't, it's a standalone special episode. it's still remains listed as an episode in the "special" season as well as being inclued within seaon 18.

it looks like that when "Display specials within their series they aired in" is disabled then the specials are not included in "next up".