Really Weird iOS URLSession https request time out, What does the log say?

I use a URLSession to make a GET request to our server, and 50% of the time it will just time out, I have captured the below logs of the HTTP transactions in the below image, can anybody tell from the log why it's time out, seems there are some HTTP connection steps missing in the “Time out” screenshot？ in the "SUCCESS" screenshot logs there are more steps inside the red box

I can reproduce it locally with the same internet environment, same HTTP request, same everything, but it just 50% chance will time out,

and here is the log of the 'Time out'

default 21:56:58.756656+0800    xxxxx   CFNetwork Diagnostics [3:3008] 21:56:58.755 {
        Did Timeout: (null)
             Loader: <NSMutableURLRequest: 0x281268b10> { URL: https://www.xxx.xxx/api/v1/search-xxx/JP/en-GB }
   Timeout Interval: 60.000 seconds
init to origin load: 0.000465035s
         total time: 60.2098s
        total bytes: 0
} [3:3008]