Does the prayer become void if the articulation point of the letter "ض" (ḍād) slips to "ط" (ṭāʾ) when reciting Allah's words: "غير المغضوب عليهم ولا الضالين" (not of those who have incurred Your wrath or of those who are astray)?

If you do not pronounce the letter ط (ṭāʾ) purely instead of ض (ḍād) in "wa la ad-ḍāllīn," your prayer is valid, and there is nothing upon you. It is permissible to follow the opinion of the Malikis, who hold that an unintentional error in pronunciation in Al-Fatihah does not invalidate the prayer. We caution you against excessive scrupulosity (waswasa) regarding the articulation points of letters.