Touch events responding is delayed when 3D touch is ON

Update:

I create a plain app and a keyboard extension to test the touch events. The plain app can respond the touch immediately but the keyboard extension has about 1s lag.

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Hi,

Recently I test my app on the iPhone 6s and the iPhone 6sp with 3D touch ON. I notice 3 strange things:

1. When my finger touches on the left edge of the screen, the app responds the touch events after about 1s delay.
2. When I touch on the left edge of the screen and push with force, the 3D touch task switcher shows.
3. But if I tap the left edge of the screen, the app can respond the touch events immediately.

I test many other 3rd apps and system apps (notes, contacts) this phenomenon exists too with 3D touch ON. When I turn 3D touch OFF, the app responds the touch events immediately as usual.

On the other hand, the system keyboard responds the touch events immediately whether the 3D touch is ON or OFF.

I guess it’s because the touch events responding conflicts with the 3D touch task switcher. I have tried many 3D touch APIs but have no effects.

Does anyone have an idea? Thanks!