why reactive failed?为什么页面数据不变

[me4405801]

test.txt
刷新页面，点击test2，页面显示正常。
bug1：刷新页面，点击test1，第1行a没有变成aaa，第3行a变成为aaa
bug2：刷新页面，先点击test1，再点击test2，第1行a没有变成aaa，第3行a变成为aaa

请问为什么会这样？如何解决？
如果我想做一个前端页面的搜索，肯定需要将原数据deepCopy一份副本，然后在副本上做一系列过滤数据操作，最后用这个副本数据显示。
源码见附件

[me4405801]

reload page，click test2，everything ok。
bug1：reload page，click test1，line 1 a do not changed to aaa，line 3 a changed to aaa
bug2：reload page，click test1 first，then click test2，line 1 a do not changed to aaa，line 3 a changed to aaa

why?

If I want to do a search on a front-end page, I definitely need to make a deep copy of the original data, then perform a series of data filtering operations on the copy, and finally display the data using this copy.
The source code can be found in the attachment

[s3xysteak]

Maybe try to repro it in https://play.vuejs.org/