StopWatch problem! Please help!

Could anyone help me?:disappointed_relieved: I got a task to fix this error in StopWatch app which was created by an off-worker, so I can not ask him anything about it.

The problem is:
the StartAll, StopAll, ResetAll works correctly for every watches, but when click Start or Stop of each watch, then I try clicking StartAll , StopAll button, all of the watches can not correctly reflected…

I am trying to do it as below…
_startAll and stopAll give effect correctly to every watches.
For example:
There are 3 watches running (ON) and 2 watches OFF.
•case1: click startAll -> 2 (OFF) watches start running
•case2: click stopAll -> 3 (ON) watches stop running.
Then try alternatively freely click startAll, stopAll, start-stop-reset(in each watches). They all should take effect to each others without miss any ones.
_when click resetAll button, no matter which watches is ON or OFF. All of them return to 0.

Here is the code, please have a look.

I am just a beginner, please tell me clearly which line of code need fixing. If you need the whole folder, please tell me.
Hope you help me!:cry: