Since Xmas, our new 55AG8 has exhibited the following. After power up, sound is heard after 2-3 seconds, picture arrives several lambing seasons later, typically 6 minutes, worst case 11mins 22secs. Normally network connection is Wi-fi but tested using wired LAN, absolutely no difference. Performed Factory reset - no change, software is up to date according to TV. Have reported to Sony, but they have suggested a software upgrade which my tv says is not necessary - who is telling porkies then?

wireless network speed 600+ Mbps, internet download speed 50-55Mbps. 

Android Oreo 8

Anyone come across this before?

many thanks