What is the authenticity of the stories circulating in Bangladesh regarding the Prophet (peace be upon him) raising his hands in prayer and saying "Ameen" aloud, and are the reasons they mention for this valid?

A Muslim should not be fanatically devoted to the opinion of any single person, for everyone's words can be accepted or rejected except those of the Prophet, peace and blessings be upon him. If the Sunnah of the Prophet, peace and blessings be upon him, becomes clear to a Muslim, it is obligatory for him to follow it and abandon the words of others. Raising the hands with the takbir is a confirmed Sunnah from the Prophet, peace and blessings be upon him, and the Rightly Guided Caliphs. The hadiths reported concerning it were from Medina, and the claim that it was to expose those who hid idols under their armpits is a false assertion. As for raising the voice with ameen, there are some hadiths that indicate it, though its narration is not as firmly established as the hadiths about raising the hands, but it is confirmed from some Companions.