hi I just bought the TCL s421-ca I wanted the 5 series but 300 bucks Canadian you can't go wrong anyway my problem is I have a Roku insignia in the bedroom and it has the feature in settings under the power menu to fast start now this TCL doesn't have that at all it's updated to the latest version and my missing something and a biggie when I turn the TV off then turn it back on I have to change all the settings back.
@ShaunTech wrote: a biggie when I turn the TV off then turn it back on I have to change all the settings back.
That doesn't sound right, and isn't related to fast-start. I would do a factory reset from the home>settings>system>advanced menu. If that doesn't fix it, I would return it to the store while you're still in the return window. You shouldn't be having problems like this with a new tv. Maybe it's in store demo mode. The factory reset should get you into home mode.
 I wouldn't use fast-start because it's like hibernating a computer forever. Corruptions in the memory become permanent. It never loads new modules. That can cause strange problems. If you ever think you're having a problem, go to the power menu where fast-start is, and do the restart there. That forces all the stale things to reload. Having fast-start disabled doesn't slow the startup that much. I've seen people say some feature doesn't work without fast-start enabled. So, my advice isn't universally true.
"People are often amazed at how much we’ve done with the number of engineers we’ve got." (Roku CEO Anthony Wood, Austin Statesman, Oct 4, 2019). "Amazed" is one way of putting it.