UC Housing costs and ASTs with less than 2 months to run

Was at a welfare benefits forum recently. The DWP partnership manager told us that UC will not accept tenancy agreement as proof of housing costs if it has less than 2 months to run.  there was an audible gasp from most people in the room!.  He could not enlighten us on what DWP would accept as proof.  Have those with more experience of UC come across this and how they deal with all those 6 month AST tenants?
Also (on a different topic) he also said that benefit advances were to be repaid over 4-6 months, not 12 weeks as CPAG states. Has there been a change in policy?