Why does adjustment layer resize move clips I want to add to it.

Not a very clear description of my issue but want I am trying to do in the timeline is extend an adjustment layer over the top of the fllowing clip. When I try to do that the clip I am trying to include simply moves along so that the AL still ends just when the clip starts.

Is there an article or helpful video that explains the interaction between adjustment layers and clips so that I can work out how to get it to do what I need it to.

I also  have a problem with altering the length of audio clips on the timeline as it often says Trim Blocked on Video 1 even though the two are not linked as far as I can see.