ASIair Pro and WiFi - help!!

[osbourne one-nil]

I have an ASIair Pro. I connect it, via an ethernet cable, to a GL-iNet portable router, which is set to repeater mode and connects to my home WiFi. My home WiFi network consists of three TP Link Decos which mean that anywhere around my house or garden I can get download speeds of well over 100mbit. 

This all works beautifully and I can connect and control my telescope when it's indoors, via my iPad, wherever I am in the house, no matter which Deco device I'm actually connected to. However....the minute I place my telescope outside, it all goes wrong and the imaging setup disappears. This is despite my phone or ipad still having a strong WiFi connection with blistering download speeds when standing next to it. 

I can't quite tell if the problem lies with the Deco (home WiFi) the portable router or the ASIair, but it's so frustrating. Does anyone have any ideas?