Does the landlord have the right to terminate the lease agreement if the tenant did not pay the agreed-upon weekly rent for the month of Ramadan, knowing that the tenant did not provide an excuse for having an accident?

Not specifying the rent for the month of Ramadan in an annual lease contract renders it invalid (fasid); because the ignorance of part of the rent necessitates the ignorance of the remainder. Consequently, there is no need to terminate the contract since it was not valid from the outset, and a fair market rent (ajrat al-mithl) is due for the elapsed period.