Is the fast of prisoners who are compelled to eat sahur after the Fajradhan valid?

It is not permissible to eat or drink after dawn becomes clear for anyone who is obligated to fast. Prisoners must raise their issue with the prison administration to provide food on time, or they should save the day's food for the next day, or keep some breakfast food for suhoor (definition), or buy food. The days on which they ate after dawn must be made up after Ramadan (definition). Fasting is a great pillar, and its reward with Allah is immense. Patience with its hardship is a sign of true faith, and whoever fasts Ramadan out of faith and hope for reward will have their past sins forgiven.