We received a detailed response from our IT/ad partner:
From looking at the comments it appears that a lot of readers are talking about the page refreshing on iPhones. This is an iOS refresh bug that's impacting most of the internet right now including major sites like CNN and Sports Illustrated. This issue is not exclusive to Raptive and is affecting other ad networks as well.
The iOS refresh is intentional on Apple's part, designed to manage memory and ensure smooth device performance. At this stage, Apple completely controls the page reset feature, which they view as a benefit, rather than an issue, and unfortunately means we can't implement an immediate fix. We are, however, actively exploring ways to minimize our memory usage to enhance the performance of our ad code.
It can vary from device to device, but clearing device cache and app data could help with that, although it won't completely fix it since Apple has the limits set in the devices themselves. It can also happen much more frequently when using a browser through Facebook, Instagram, etc as those apps can add additional memory to the page experience which causes the refresh issue quicker.
For users of Android phones, Android also has a memory saver function that performs the same function of refreshing the page, but it can be disabled. If able, you can instruct the user that reported the issue on Android to do the following, this should help:
They can disable Chrome's Memory Saver feature to prevent tabs from being refreshed automatically. To do this, open Chrome, tap the three dots in the top right corner of the screen, select Settings, scroll down and tap Performance, and then toggle off the Memory saver switch.
Resource here.