Hi beiriannydd,
for this kind of design, it could be worth considering the sweep tool.
Hi Peter, @Peter_Gy I think also this behavior of the loft tool is not the expected one. To the user point of view, there is no obvious reason why the loft tool fails to create a simple hollow cylinder but succeeds creating half of it.
I do agree also with beiriannydd that you should be able to select multiple coplanar faces; I have quite often to modify a sketch just for the loft operation (changing temporarily some lines into construction lines so there is a single face to loft from).
Best
PEC