I would agree with Creative on this if it is what I have seen.
I might also guess that one has come unsnapped or the metal bracket come loose.
I tried to do a bit of crude drawing for what I might expect if we looked at the shade from one end. guessing there are two metal brackets as shown, one somewhat near each end.
If this was looking at left end with metal top of shade and shade hanging down?
Maybe if you picture holding your hand out with the fingers down like you were going to pick something up?
Your fingers may a space where they point in toward the shade, much the same as the shade. Then there is a groove running along the back of the shade metal part, as well as a groove on the front.
On the front of the bracket, there may be a tab sticking out maybe 1/2 inch long?
Idea to put them up is we need to stick the metal up to fit the back groove on the back like where our fingers might be in my crude example.
Then step 2 is kind of "rolling" the front of the shade up to let the front notch fit into the groove.
Problem?
This little bracket tends to be way stiffer than I might like and it fights me when I try to force the shade up and in!
We have done it by letting my wife move the shade while I push up on the tab as it spreads the opening just a slight bit IF I can press hard enough and she can wrangle the shade!
If you stick your fingers up in front of the metal and along behind the front piece, you may feel the bracket that is still attached as you feel along that space? Right and left side may be about the same distance in from the ends to help locate the left one if it is loose from the wood and still stuck to the shade metal?
Not an easy thing to describe but maybe some ideas to help?
Good luck and be aware that I have trouble every time we get one loose!
