Some pages use 'modern' page controls that don't actually take you to another (URL) web address. The only way to navigate these javascript sites is to use the back/forward/page controls on the actual site, not the ones in the browser's control bar.
That said, I played around with a couple of Google Searches in Safari on the iPad, and the back and forward controls seemed to work fine; though I noticed (for the first time) that Google seems to have changed up it's default appearance for the iPad to a more card focused model, with it's own simplified forward back controls at the bottom (no more page numbers).
It could have been that way for a while, and I just have not noticed.
I'm not saying you don't have a problem, just that I've failed to duplicate it, and that makes it darn hard top figure out what's going on.
So, all I can really offer is some advice; the way I handle my own Google Searches. Once I have a set of Google Search results I like, instead of tapping on the links I tap and hold on the links I want to explore, then open them in a new tab. This leave the original search page untouched so I can go back quickly, and as often as I like.