Hold/Power button Won't Click

I repair iPhones as a side job kinda thing, and I recently have opened up and attempted to fix a hold button, however, the hold button will not click like it normal should would I assembly all together. It is just too lose/tight depending on how I move it, but I can't get it to trigger the button underneath.... Totally cofused here as to if the button is suppose to be placed in a certain way. Anything helps, and if anyone could direct me to a video or tutorial that would be great, thanks!