Kuba,
Multipage formfunction works fine in the cloud. I tested your code and it works. If I enter 3 in the rooms field it delivers 3 input fields when next is pressed.
CloudDeploy@FormFunction[
{
{{"rooms", "number of rooms"} -> "Integer"},
Table[{"room" <> ToString[i], "guests in room" <> ToString[i]} ->
"Integer", {i, #rooms}] &
}]
If you evaluate in the desktop it is also fine. (note the [] at the end to launch the form)
FormFunction[{{{"rooms", "number of rooms"} -> "Integer"},
Function[
Table[{"room" <> ToString[i], "guests in room" <> ToString[i]} ->
"Integer", {i, #rooms}]]}][]
Could you be more specific on what it is that is not working? (I tested 10.1 kernel, win7 64)
