A non-blocking socket operation could not be completed immediately.
The extended error suggests that an attempt to read from the socket has simply failed because there is not yet any data available. A common condition with non-blocking sockets.
That is -- and this is wild speculation -- the module has probably issued/sent the command to the server; and then entered a read loop in order to retrieve the output; but as the socket is non-blocking, instead of waiting for the output to be available, it is assuming the command has failed rather than retrying.
Just a guess, but one that fits the scenario.
Given that your code can do nothing else until it gets the output; why are you setting it non-blocking? Is the module designed to be used that way?
(Note: I've never used the module and know nothing about its internals or use. But maybe this speculation will help you?)
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In reply to Re: Error - A non-blocking socket operation could not be completed immediately.