Problem : I use OnPressed button event, and set timer. On 4.17 the OnPressed only register for ~0.8secs then the touch un-register automatically.
I try to reproduce on 4.16, it works fine, no touch auto un-register. I believe this may be a bug on 4.17.
Turn out the problem is button have one parameter Is Focusable
Solution : untick the Is Focusable and its working perfect