If this happened only with the Navdata enabled, it's very likely a problem with it, since GSX is most likely the first add-on that use it, so we are all testing this. However, the Couatl program has been designed to be started or restarted manually and, in fact, there's no reason to use it while you are flying, if you start it before landing ( if you want to pre-select a gate ) or even just after landing, it will work just fine, and has been made considering this usage case, this way you won't be affected by possible issue with Simconnect, that seems to sometimes just stop talking with add-ons, especially if you have more than one connected to it.