Disable split screen on Huawei Honour 9?

[ObliviousNinja]

I recently upgraded to the honor 9 after using a Huawei P9 for a while. I've noticed that I sometimes accidentally put the phone into split screen mode by long pressing on the recent apps button on the built in navigation bar. I find this feature potentially useful but really annoying when I don't want it, so I was wondering if anyone knows a way to disable it. I've already disabled the knuckle gesture for it, but I'd like longpress on recent apps to just do that, and disable the split screen mode permanently. My device isn't rooted, so I imagine this might be difficult...