Hello,
I tested your code and cannot confirm your bad observations.
With the three working urls your sketch is now running for a some minutes flawlessly.
For www.howsmyssl.com wireshark reveals an ssl handshake failure, see picture.
It’s strange, that on wireshark I cannot even see a DNS request for this url.
Are you sure, that you have the latest firmware for the Wio Terminal installed?
There are some posts in the forum how to install the actual firmware in the Arduino IDE.
framework-arduino-samd-seeed@GitHub - Seeed-Studio/ArduinoCore-samd
However, I also saw occasional hangs and stopping of performing http post requests.
https://github.com/Seeed-Studio/Seeed_Arduino_rpcWiFi/issues/9
I would be happy if the cause of this were in my App, but I suspect that the reason lies in the Seeed libraries.