When i downloaded some DLCs from steam, only woodhead line and isle of wight showed, does someone know the soution for that?
Check the new content is ticked in your owned DLC list. Completely exit Steam and shut down restart PC then start Steam might kickstart it. As a final resort, do a Steam file verify.
Trains need their respective routes to show up. Also, despite layout, QD loco filters by route electrification. If not resolved, post the entire list of what you have installed.