"No Service" on WiFia with good signal.

OK, that did get answered. Thought I missed something.

Just like title says
Why would Wi-Fia show "No Service" with perfect signal?
And phone with different carrier did the same?

Maybe we have not explained properly or don't understand your question.
The first question was "What da hack those electronics do?" and just above you ask "My question is just out of curiosity if anybody would know how the system is set."
Could you clarify what it is that you are trying to understand that has not been explained properly?

you should check there data coverage map where are you? sprint data map click on the data tab and zoom in to where you are.

I bought Wi-Fia about 6 months ago. It works most of the time and to date it is always faster than campground WiFi, so hearing about all the problems with the system, can't complain.
My question is just out of curiosity if anybody would know how the system is set.
Evidently nobody can answer that.
My guess is that in areas like beach, with lot of tourist the system might limit data to leave phone connections for important stuff.

Thanks for the info. I have a Sprint MiFi and it does not use that name but I will not dispute what you say. Is this something you have had for a long time? If so, that may be the problem.
I have a Sprint Netgear Zing MiFi and there is/was another available when I bought a couple of years back but can't remember the model. If I Google Sprint MiFia/Mi Fia I get nothing.

Wi-Fia is Sprint name for their Mi-Fi. Works (or doesn't) the same way my old MiFi did.
No, I don't see it as separate Wi-Fia issue as my Tracfone did not allow data as well.
Than again I had 2-3 bars out of 3 on my modem for signal strength and "No Service" display.

Sounds to me like issues with your MiFi device assuming that's what you have. Not sure what a Wi-Fia is but I am guessing you really have a MiFi device. The MiFi sends out a signal to your other computers via WiFi just the same way that a campground would provide WiFi from their router to your computer.
A no signal message would mean that the MiFi device is not seeing ANY usable signal from the tower and this should not change while staying at the same location unless someone moves in between you and the tower or your device is overheating or having some other issue which causes it to shut down for a period of time before becoming usable again. Be sure it's out of the sun as that's a killer!
When the MiFi device is showing that service is available, the number of bars is not a determining factor with speed. More bars "can be" better but is not the #1 thing that would let you know whether you should be getting great speed or not. You can be on a fully loaded tower with 4 bars and the speeds can stink and you can be on a lightly loaded tower with 1-2 bars and the speeds can be excellent.
This is also vary by time of day and whether it's a weekend and all the kids are on their computers and phones. Evenings can be the worst as everyone is home every where and they are all on their devices, many of them streaming Netflix and the like.

Sprint is not known to be a good service for travelling.

Let me say it different way. When my WiFia modem do have its migraines, at one Lake I did not have data service on both - modem and android.
They have different providers and again - signal was good on both, yet seem data transfer was block.
Then yesterday the modem would transfer the data, while showing "no service". I left it on overnight and it is showing service now.
All of that has nothing to do with WI-Fi provided by campgrounds.