I submitted a LNF claim for one of my upcoming stays and it was only partially approved. Since the comparison site did not give a daily breakdown of the rates the agent took the Avg Daily rate (ADR) and only comped the nights for which the ADR was lesser than the marriott booked rate.
The reservation is for 3 nights with rates at 313,254,254 so with taxes it comes to $911.2. The comparison site had a rate of $872 all in - I was very happy when I found this and thought it would be approved at $654 all in which is a great rate for that property at that time.
The agent took the Avg Daily Rate at the comparison site which came to $264 and since only the first night had more than this rate applied LNF only for that night. When I called the agent said thats how its done for sites which do not show a daily breakdown and insisted thats how it always has been. I just hung up.