I would like the issues and laws to be identified if possible.

If the lessor tells the lessee that they would reduce the rent by 40% till the end of their lease (2 years) given that the lessee has been experiencing hardship due to the pandemic, however the Lessee's sales have picked up. The lessor emails them (july) that the discount of rent will end in September and the lessor may even claim the rent backdated from june