Toyota tundra loose timing chain because of default cold start timing

I have a 2014 Toyota tundra SR5 5.7. flex
Tensioner was replaced do to chain slap.
Changed chain and all tensioners.
It did it again after 2800..00.
The tentioner is new but the vehicle at cold start retards timing and causes chain to run loose until vvt adjust time takes about a minute or so then is quite. So tensioners are fine and working. Ethanol sensor samples fuel at startup and defaults timing. I don't know if it is the sensor that it defaults to.
Spent 8000 at Toyota to no resolve.
Does anyone know what in the systems cause the computer to default on cold start up?
Fuel, air, temp?
Oil pressure is tested good. But at cold start something tells the vvt silinoids to correct timing. Runs great but have to wait for it to time.
No engine light codes ever.