(I used these documentation past years, I don't know if it are useful for other channels).
One more thing, in your screenshot the line highlighted is "hard" type. Perhaps the WeChat service works as for MX or SMS platforms, by delivering feedback later and so putting it in hard bounce the quarantine record, after X soft bounces trial to resend (as for mails management ?).
How is defined the delivery WeChat in the Send tab, section of consecutive trials of the Properties form ?
It seems you are getting exceptions when you are executing try block. It may happen because your Third party system(Subscriber) is not working or taking longer than expected and you are using a for loop in your try block to initiate the second request.
I can't say with certainty what the problem is but if you can share the code from the try block, it would be easier to help you out.