It worked flawlessly in 4.19 on all devices, i’ve seen some reports it breaks down in 4.20+ on moto G5, for example. https://answers.unrealengine.com/questions/787556/getinputmotionstate-returning-all-0-values-for-som.html
Try just blank project on older versions of engine, not sure if it’s a bug that’s been there, or introduced in newer UE version.