Vibration api

Question

Why vibration api don't working well below 5000ms . While I have seen in various tutorials that they do it at even 100ms and make a tone pattern.
You can check my code here for test and errer if any .

https://code.sololearn.com/WBwudaYrf7gi/?ref=app

Answer 1

It's working fine, even with value below 100.

Answer 2

I am using android and it's working well above 5000 but not below it.
By the way
Thank Calviղ for response that is working well on other's device.