Well, that depends mostly on your usage. A 7 Plus with 3 Gb of ram shouldn't do that so often, but it still can happens if you keep a lot of webpages open while switching between apps
It's no big deal to me either but I've definitely noticed it a couple times. I just thought it was the webpage trying to get more clicks or something. LOL
Most of time it won't reload the page. Which is more that can be said of my old s7e.
Btw I'm happy to see that 3dt party keyboards stay now as main keyboard. On my old 6 it allways reverted back to the stock.