To what extent is the hadith "I seek refuge in Allah and His Messenger from being like the delegate of 'Ad" authentic, given the contradiction with the impermissibility of seeking refuge in a created being, and Al-Albani's authentication of it?

The authenticity of the hadith with the wording: "I seek refuge with Allah and His Messenger" depends on the authenticity of the narration. The narration by Affan is more reliable than the narration by Zayd ibn al-Hubab, which includes the wording "and His Messenger."

If the narration with the wording "and His Messenger" is authentic, then seeking refuge with a living, present creature in matters within their capability is permissible. This differs from seeking refuge with the dead, the absent, or in matters that only Allah can accomplish, as that would be polytheism (shirk).

Evidence for the permissibility of seeking refuge with a creature in matters within their capability includes: the hadith about tribulations, "So whoever finds refuge from that, let him seek refuge in it"; the story of the woman who sought refuge with Umm Salamah; the boy who sought refuge with the Prophet (peace be upon him); and the story of Aisha (may Allah be pleased with her) when she said to the Prophet (peace be upon him): "I seek refuge with the Messenger of Allah from him cursing me today."

Therefore, Al-Harith al-Bakri's seeking refuge with the Prophet (peace be upon him) from being like the envoy of Ad is considered permissible, because he sought protection from him (peace be upon him) in a matter within his capability.