There are some other complaints about HDMI handshake issues with certain tvs after the box has been off for a while - not sure if they were with the Xi6 or XG1V4 or both. It may be that the box or tv or both have gone into sleep mode and one is not responding to the other in time. If unplugging and reconnecting the HDMI cable wakes it up, that is probably the issue. You might try turning off sleep/low power modes on the box or tv or both and I think there is at least one report of a new HDMI cable helping.
I think this is a HDMI handshake issue between TV and the Box. I have the same issue, and I have to turn off my TV and restart the TV Box first, then turn on the TV after the TV Box finish boot.