chrome still running when timeout

[huelsgp27]

 Browsershot::url($url)
                ->format('A4')
                ->waitUntilNetworkIdle()
                ->timeout($timeout)
                ->noSandbox()
                ->save($distPath);

Show processes:

#  ps  xao pid,ppid,pgid,sid,comm | head
  PID  PPID  PGID   SID COMMAND
    1     0     1     1 tini
    6     1     6     1 php
    7     6     6     1 php
    9     7     6     1 php
   10     9     6     1 node
   33    10    33    33 chrome
   35    33    33    33 chrome
   36    33    33    33 chrome
   68     0    68    68 bash

After the timeout:

#  ps  xao pid,ppid,pgid,sid,comm | head
  PID  PPID  PGID   SID COMMAND
    1     0     1     1 tini
    6     1     6     1 php
    7     6     6     1 php
    9     7     6     1 php
   33    1    33    33 chrome
   35    33    33    33 chrome
   36    33    33    33 chrome
   68     0    68    68 bash
  101    68   101    68 ps

The node process has been killed, but the chrome's ppid becomes 1 and never exit, which lead to memory leak.