I am booked next monday BRU-FRA-IAH in business class, on a full flex, refundable business class ticket.
I would like to depart already sunday late afternoon and stay overnight in FRA to be sure that I have my flight monday morning to IAH. So I asked our travel agency to change the booking. They came back and say this is not possible, because it is adding a stop !
I was very surprised, because the routing doesn't change. The only thing that changes is that instead of having a connection of 2 hours in FRA, I would be about 16 hours in FRA (not really at the airport, but of course in an airport hotel)

I contacted LH directly, but they tell me I have to go via the travel agency.

Is what the travel agency says correct ?

Luc