Is it crashing on its own, or when a certain app is running?
I have had 2 ATV4 since they first came out, on tvOS12 now, and don't recall ever having them crash. I have had some apps that crash, and I typically reinstall these apps. Also, a reboot before reinstalling might be a good idea, a power off restart to make sure everything from the old app is cleared.
On ATV3, all apps probably went through more scrutiny from apple given no app store. but with ATV4 and later, devs submit apps for review and pressure is on apple to approve. So, chances are more sloppiness gets through.