Focus search continues to fail with an external lens, camera2 api in android

Question

I am using camera2 api for my custom camera. I implemented a touch of focus. It is working fine. But when I try to connect an external lens, it cannot find the focus distance, I have to try several times. The native camera works great even with a lens. What else should I consider? Any opinions? please guide.

Answer 1

(For future reference) I finished the solution using samsung camera sdk . It works great