I bought a Vizio TV which has this evil, undocumented "feature". It would pop-up a message after every dozen or so boots. The message can be manually dismissed with three clicks on the remote.
The TV also will not turn on and just display an external HDMI source even though it has a "Remember Last Source" feature. That feature does work with any internal streaming source but external sources must first be manually selected with the remote after each power on (also undocumented in the manual).
I figured this out because I bought this small TV to be a wall-mounted screen in the dedicated bathroom of our home theater room. It's only job is to turn on while someone is in the little bathroom and display a copy what's on the main 150" projector screen in the next room, then turn off when they leave. The on/off is handled by a motion sensor and standard Home Assistant automation but after power on it correctly shows the Last Selected external HDMI source for 1 second, then blanks the screen. The source is already selected and working but being blacked out until the remote re-selects the same source (only if it's external). This is clearly an undocumented anti-pattern added specifically to prevent the TV being used unattended as a display screen, picture frame, digital sign etc. Why? Because Vizio (now owned by WalMart) doesn't get rev share if it's: 1) Not online, and 2) Only viewing external sources. That's why it demands manual "proof-of-life" before it'll grudgingly deliver the basic functionality it claims on the box.
So, I programmed an ESP32 with an IR emitter so that every time the TV powers on it sends the remote presses to manually clear the "Please Connect Internet" message and re-select the already-selected external HDMI. Very annoying to be forced to figure this out but now it works fine and no one even sees the stupid messages as they're already gone before they see the screen. Fuck Vizio :-).