Player can scroll through walls on ipad???

Has anyone ever encountered this problem? A player using an ipadAir for my campaign can two-finger scroll their view around the entire map. Her character's token vision stays locked in place but by two-finger scrolling around the view moves all over the map, through dynamic lighting walls. She's able to see monster tokens I've placed in different rooms. We've tested this on different days having signed out and back into the game, so it must be a setting? But also this isn't happening on any other device, so it may just be roll20 interacting with her ipadAir in buggy way? The problem is that her laptop is ancient and can't run roll20 without significant lag and the ipadAir is much newer (os 26.3) and can run roll20 just fine minus the clipping through walls. Has anyone dealt with this and know how to fix it? I'm a newer roll20 user so any suggestions would be helpful. Thanks in advance.

I’m guessing the issue is a browser issue, and there may not be much that Roll20 can do to prevent it. But hopefully devs can respond about that.  One thing to know about Apple mobile devices (iPads and iPhones) is that Chrome and Firefox browsers are not true independent browsers; they are still Safari but with an overlay, so some code (such as JavaScript) will work differently than Chrome or Firefox on a laptop or computer.  If that is the case, then the only option will be to ask your player not to cheat, or to use another device that doesn’t have those browser limitations. Unfortunately Roll20 is only optimized and configured to work on Chrome and Firefox on computers, so while devs may be able to do something to prevent this, it’s also possible they can’t and or won’t. 

First, as GM, make sure that you have "Lines Block Movement" enabled on the Page Settings. Next, I'd say have the Player try it with different Browsers (Chrome or Firefox) on the iPadAir.  Yes they may be reskinned versions of Safari, but Chrome browser installed onto the iPad may work better for this.