internet browser tabs keep reloading

On my iPad mini 1 (iOS 8.4.1), if I switch from Safari/Chrome to another app or between tabs, then switch back, the page is often reloaded, which wastes time and means any input text or other unsaved modifications to the page are lost. I haven't seen this happen on my iPhone 5. Is this due to the chip (presumably A5 on the iPad, A6 on the iPhone) or something else, and is there a fix - as it tends to cause issues at least a few times a day?