I am enquiring about my wife's gmail account on her iPad. Until recently all links worked satisfactorily and opened in Google easily. Suddenly this has ceased and whenever she clicks on a link in gmail, google opens but it goes to the default page and does not open to the link. I have been through all the settings that I can find but i don't seem to be able to get it working again.
I had the same problem. One suggestion on the web was deleting the gmail app from my iPad and downloading it again. I tried that, but I couldn't download the app again because it said the new version of gmail didn't work on my old iPad. So now we know why the links weren't working.
So then I went into Google on my iPad and opened my gmail account from there. It's not as convenient as using the app, but at least the links work fine.