select 与 time.After 配合使用的问题

今天在工作中发现了一个有趣的现象。

在一个select中设定了两个定时器，本来预计哪个定时器到达就运行相应指令的，但是发现最终只有时间最短的定时器一直得到执行，其它定时器完全没有得到执行。

package main

import (
"fmt"
"time"
)

func main(){
    for i:=0; i< 3;i ++ {
        select{
            case <-time.After(7*time.Second):
                fmt.Println("1 second")
                
            case <-time.After(5*time.Second):
                fmt.Println("8 seconds")
        }
    }
}

服务器输出是：

8 seconds
8 seconds
8 seconds

在stackoverflow上有人提到了，time.After每次都会返回一个新的channel，所以select不可能监测到新产生的channel：
https://stackoverflow.com/questions/39212333/how-can-i-use-time-after-and-default-in-golang

package main

import (
"fmt"
"time"
)

func main(){
    count := 0
    timeout1 := time.After(7*time.Second)
    timeout2 := time.After(5*time.Second)
    for i:=0; i< 36; i++{
        select{
            case <-timeout1:
                fmt.Println(count, "7 second")
                
            case <-timeout2:
                fmt.Println(count, "5 seconds")
                
            default:
                fmt.Println(count, "Just wait")
                
        }
        count++
        time.Sleep(1*time.Second)
    }
}

0 Just wait
1 Just wait
2 Just wait
3 Just wait
4 Just wait
5 5 seconds
6 Just wait
7 7 second
8 Just wait
9 Just wait
10 Just wait
11 Just wait
12 Just wait
13 Just wait
14 Just wait
15 Just wait
16 Just wait
17 Just wait
18 Just wait
19 Just wait
20 Just wait
21 Just wait
22 Just wait
23 Just wait
24 Just wait
25 Just wait
26 Just wait
27 Just wait
28 Just wait
29 Just wait
30 Just wait
31 Just wait
32 Just wait
33 Just wait
34 Just wait
35 Just wait