Is it obligatory to repeat the ritual bath (ghusl) and the prayers that followed it due to doubt about water reaching all parts of the ear, given the presence of a white substance inside it during the bath of janabah?

If doubt arises concerning the thorough distribution of water during ghusl after its completion, it should be disregarded.

The predominance of belief that water has covered the entire body suffices for the validity of ghusl, and certainty is not required.

However, if the doubt occurs during ghusl, and the person is not prone to excessive doubts, then the part in question must be cleansed.

It is permissible to adopt the opinion of Sheikh Al-Islam regarding the excusability of a small amount (of an obstruction) that prevents water from reaching (the skin).

Succession (Muwalah) in ghusl is a Sunnah, not an obligation. If you doubt a small part, it is sufficient to wash that specific area with the intention.

It is obligatory to repeat the prayers that were performed with an invalid purification, while striving to estimate their number.