Raise Rent for Tenant Paying Less Than Lease

[Rob Stein]

I am hopefully going to get a duplex under contract next week, each unit already has tenants on current leases. In one unit, the rent is 2,200 a month on the lease, which the tenant was paying, but lost his job and the current landlord is allowing him to pay 1,800 a month. There’s also wording in the least that says the tenant can renew the lease at current rates. My question is, if I take over the property, should I wait until lease renewal in November to ask for the 2,200 a month, or sooner? The 1,800 is an informal agreement between the tenant and current landlord, the lease says 2,200. Thank you so much for any advice or thoughts!