The WiFiClient uses Stream::_timeout for connect() timeout, write() timeout, hostByName timeout.
Is that intended? Default value of Stream::_timeout is 1 second. WiFiClient changes it ti 5000. That is too much for Stream timed read functions like the readBytesUntil function.
Other libraries haveclient.setConnectionTimeout. It was first used in the 2.0.0 version of the Ethernet library in 2018. There it is used in client.stop() too.