What iFLy "unit" are you using?
It sounds like the iFly device is preferentially connecting to another available network instead of the Stratux. Depending on what your iFly device is and how you use it, the "easiest" solution may be to delete all the other networks so that it only ever tries to connect to the Stratux.
With tablets and phones, it's pretty easy to quickly change the device to connect to the Stratux if it intiially connected to some other wifi network first. With the dedicated iFly devices (720, 740, etc.), it's not as easy / seamless to bounce between different networks.
I have my 720 set up to only connect to the Stratux network. If I want to update the data on the device, I pop the SD card out, stick it into a Windows laptop, and run iFly Connect there, download the data I need, and then move the SD card back to the iFly device. I avoid trying to use the iFly device on multiple wifi networks because of issues similar to what you described.