iPhone appears in Ethernet when logged in to Guest network and has no Internet

[Guestnetwork]

I have set up a Guest network via Vodafone Broadband App for the first time and all is looking good.

But when connecting with an iPhone SE to Guest network the device shows up under Ethernet and not in the Guest network, which is rather strange because it is recognized as mobile phone.

There is no error message but online services are not available despite the device not being blocked.

Cannot figure out what is wrong, maybe something needs to be configured in the Router settings?

[Jayach]

Which router do you have? 

[Guestnetwork]

Productname : Vodafone Wi-Fi Hub
Firmware-Version: 19.4.0551-3261103
Model No. : THG 3000

Apparently the "Guest network" has been implemented as "WiFi 2"

I have not yet tried to separate frequencies, which is unlikely to cause the issue.

Through the Android App I could block/unblock the device giving access to "WiFi 1" but this has downsides, like requirement to actively manage and providing the main WiFi password.

I did not expect this kind of problem and was too lazy to replace the Vodafone router by my old Fritz!box 7530 from a previous Zen contract, which I will do if I get it not solved over the weekend. (I have my Broadband login credentials.)

The Fritzbox is superior in every aspect, especially web access management and guest/children restriction setup, a cool thing is that it allows to issue one-time codes to extend your limited time slots or contingents.  Last time I checked with Vodafone child protection options (a while ago) they offered an app subscription for £1 per child per month, very customer unfriendly, and available for free with AVM routers (Fritzbox).

[Jayach]

I have the same router, but don't have an iPhone, but connecting my android phone, the Guest network (Wi-Fi 2) shows it connected as we would expect. 

What you are seeing, is what I would expect if it was connected via an Access Point. You don't have any of those, and are connecting to one of them? (if they have been setup to use the same SSID's as the main router that would explain it)

[Jayach]

As it happens, I do have an AP setup, and to prove it shows as connected via the network, here is what I see if I connect the same phone via the AP. 

Note: pictures on here can take ages to be moderated.

[Guestnetwork]

Thanks Jayach, still cannot see the pictures but I think I get the idea.

No, I am not using an AP and it looks like that the issue lies with the iPhone SE.  When connected to the main Wi-Fi, it does not show the mobile phone icon in the app and a different MAC address (virtual iOS generated for security); an Android mobile and an iPhone 7 are identified correctly.
I could swear I switched the MAC address randomization off for testing and it did not help with the Guest network, but I will try again.  For the time being blocking and unblocking in the main Wi-Fi has to do and the Guest network is useless for the intended purpose.

The wrong (or incomplete) identification of the affected device might be cached in the router, I will see if it behaves different after a reset.  I would really like to enjoy my Sunday instead of coping with Vodafone router firmware issues, after all I will decide to use a proper router to get the job done - the typical time-is-money tradeoff.

[Jayach]

I think the pictures haven't been moderated because it's the weekend.

Yes using your own router (especially as you already have one) seems a good bet

I can't see it appearing in the "wrong" place on the configuration is stopping it accessing the internet, so I imagine that has a different cause.

[CrimsonLiar]

Seeing @Jayach 's image reminded me of another time you can see this happen.  You'll see the very same thing if you've set up the Wifi on a computer as a "hotspot" on the LAN and the phone is connecting to that rather than the router!  It's the kind of thing people do and then forget about!

[Guestnetwork]

Thanks guys, I tried systematically every setting and configuration with two iPhones and an Android mobile, and eventually got the devices in "Wi-Fi 2" (Guest network) after splitting the Wi-Fi in separate connections (2.4/5 GHz)

The screen shots show the situation before and after the splitting, however this is not acceptable but at least a proof of concept.  Definitely no Access Point (physical device) or Hotspot (connection sharing) present or configured.

Device was listed (greyed out) with no InternetDevice in Wi-Fi2 only after splitting Wi-Fi

I will block/unblock device via app in main Wi-Fi rather than splitting connections by frequency and in 3 weeks I am with a new provider (cheaper, shorter contract duration, a Wi-Fi 6 router for £10 one-off, and a £110 Amazon gift card) - cannot be worse and allows also using own router alternatively, which connects my DECT handsets wireless to SIP accounts and IP landline.