I also seem to be experiencing a similar problem with connecting my iPad to my Sky Q box and seeing recordings in the Sky Go app.
I use a plug in Wifi repeater/booster to increase my WiFi signal strength in upstairs rooms (further away from my router) and have found that this is where I experience problems. If I move to near my main Sky Wifi router and reboot the Sky Go app, I can connect to the Sky Q box and see my recordings. When I then move upstairs, everything remains fine and I can play them.
This is a bit of a pain, but not too big a deal I suppose. Hopefully a future app update will fix it. My networking knowledge is nowhere near good enough to work out a fix in the meantime - any suggestions welcome.
Update - I just tried this again, but it didn’t work. I must have just got lucky first time around