Who I have the same questioned this solution

I haven't noticed any problems other than this one.  It's been happening sporadically for a while now (definitely months) but in last few weeks it's gotten to be really bad.  Before that it was just the occasional message that got sent twice.

I've had the network extender for probably a couple of years now. It's pretty much a necessity where I live. (Unless some enterprising cellular network decided to actually invest in rural Minnesota...)