You know, I am not great on computers. I happen to know about this problem, because it has happened to me too!

I personally do not like hyperlinks, as a reader, either. One never knows where it will take you, and I am paranoid about the net. The new Firefox updates have removed the "properties" that would show when right clicked...I used to screen hyperlinks before considering clicking on them. Now I can't even do THAT anymore ...sheesh.

To make matters worse, when PubMed upgraded their site recently, this did affect the addresses on some papers you may pull up. Some of the addys on them, don't work as links here at all...they show up as text only. This happens when you go sideways in a search using the right hand of the page listed suggestions for similar papers. But it also happens when you enter from Google. But it doesn't happen every time. I find this new development very frustrating to copying things to help people on this board. I don't understand it, either...and I know others have run into it and mentioned it to me.
What does work in cases when the links go into text, is to copy the PMID number off the bottom of the abstract, open a new PubMed window and put that into the keyword box. It will bring up the paper, and that addy typically is useable for some reason.
Also any link you copy that has ...... dots in it, to abbreviate in a format will not copy over. Those dots do not show if you hit "quote" and view the box and url. The full url will typically be in brackets and you can copy/paste it without the url tags then into a new reply box if you don't want to open a new window and go to the link itself. I find either is about the same timewise, so I go to the original link, accuracy.

So basically I just always, go to where I am trying to copy and use the original address. The various formats just all seem conflicting more so now. I also find it hard to put into words, this convoluted problem, so I hope you are following me.