If he repeats al-Fatihah or the tashahhud because he thinks he omitted part of them, should he do the prostration of forgetfulness (sujud as-sahw)?

Following the imam in the prostration of forgetfulness

Ruling On Forgetting a Prostration of Forgetfulness

What to Do If There Are Two Reasons for Sujud As-Sahw

If a person forgets a Sunnah of the prayer, should he do the prostration of forgetfulness?

The difference between uncertainty and forgetfulness… If there is a great deal of uncertainty, then it is waswasah (intrusive thoughts) and no attention should be paid to it

If he starts to get up for a fifth rak‘ah and the people say “Subhaan-Allah” before he has stood up completely, what should he do?

If the one who is praying behind an imam says the tasleem before the imam

He has a sickness that makes him unable to remember the number of rak‘ahs and prostrations; should he do the prostration of forgetfulness?

What should a person who joined the prayer late do, if the imam made a mistake and said the tasleem after the third rak‘ah of a four-rak‘ah prayer, then remembered and stood up to do a fourth rak‘ah?