Same here with UE-16448answers.unrealengine.com/questions/234834/nav-link-proxy-smartlink-functionality-doesnt-work.html
NavLinks are something what was here and working since first version and now it is broken. It is gamebreaking bug for me, so I need to stay with older version. It is probably some minor bug in code and just because of that I need to skip version 4.8 because Epic includes mostly only crash fixes into hotfixes. I can just hope that there will not be some other gamebreaking bug in 4.9 because I would need to skip that version too…
From what I see 4.9 will be common build and it will not be just about super stable build, so maybe it is good to start requesting 4.10 as super stable build with fixes only. (4.10 is much better name for special update, heh)
Anyways, I enjoy UE4 and I hope you hear as and find some solution.