Apple tv 4 Crashing,unstable,white screen etc...

Intermittent problems are often a result of interference. Interference can be caused by other networks in the neighbourhood or from household electrical items.

You can download and install iStumbler (NetStumbler for windows users) to help you see which channels are used by neighbouring networks so that you can avoid them, but iStumbler will not see household items.

Refer to your router manual for instructions on changing your wifi channel or adjusting your multicast rate.

There are other types of problems that can affect networks, but this is by far the most common, hence worth mentioning first. Networks that have inherent issues can be seen to work differently with different versions of the same software. You might also try moving the Apple TV away from other electrical equipment.

The following article(s) may help you.

Troubleshooting Wi-Fi networks and connections

Recommended Wi-Fi settings

Sources of Interference

Wifi Diagnostic Software (for Mac users)

You may also find some help on this page, where I’ve collected some of the more unusual solutions to network issues.

IT may not be, but IMO interference or network settings are responsible most of the problems raised here, I do think it's worth looking at first.

Interference is still possible with ethernet, however not really likely unless you have electric cables running along side the ethernet cable is all something like that.

There could be direct interference if ATV was beside a string emitter, like a computer, game system, etc. That might be affecting the ATV circuits directly/