have u tried logging in iflix with tablet or phone?

if it works, it confirms it is not yr unifi problem but the device.
iflix, astrogo, hypptv everywhere... are all sensitive to certain devices, don't work on some.

but usually all OK for mobile devices.

netflix not working on yr sony tv... already discussed in another thread.

now, iflix not working on yr unifi stb, right?

if iflix is working on mobile devices with same unifi but not the device, the problem has to be the device.

either incompatible or u hv not done some work on the stb. this issue, best ask in hyppbox thread - i think some succeeded, some fail like u.
https://forum.lowyat.net/topic/3594298/+2560

smart tv and hyppbox are typically poor devices, limited in capability, flexibility and memory.
really, if u r into these apps, u may want to consider a better box to handle these apps. some boxes can handle these apps very well w/o much effort.
https://forum.lowyat.net/topic/4200167