Hi [NAME],   There isn't any button/latch to press to pull out the rail extension. Can you try to remove the rail from the rack and try to check if the rail extender can be pulled out?    Ref ReadyRail video on rail extender: [URL]
I recently purchased some rack rails. I can mount them just fine. However, only one of the two will extend. The other appears to be stuck. Is there a button I need to press to get them to extend? I can jiggle the inner rail about 0.5cm, but that's it; it won't extend. Not sure if I'm missing a button somewhere or if I just got a defective rail.
Rails Won't Extend