No 4g on new samsungs

[tomm2000]

On a voxi sim only deal. I have used the sim for a few years in refurbished phones to keep the cost down.
 I've gone from Samsung S8 to S10 to Pixel 5 with no issues at all. 
 Thought I'd move to a Samsung S21 but no matter what I tried, I could not get 4g... just stuck on really slow "H" status.  Checked APN settings many times. Factory reset.  New sim.... Nothing worked. Yet I can pop the sim into any of my older phones and the signal is great again. I put it down to the mobile so returned the S21 and got a S21fe instead.... Same issue.. No 4g or 5g!
 So I'm stumped again (as are voxi customer support ) I'd love to get the S21FE signal working as well as it does in my older phones. Could anyone point me towards something I may have overlooked in the settings to solve this please? 

[AnnS]

Just about all I can think is the network mode in your connection settings @tomm2000 but if you have checked the APN settings you have probably already made sure this is set to 4G.

[tomm2000]

Yeah... Tried a few variations on the APN settings but none work. Even copied settings from my older phones (which give me 4g anf 5g) but no luck. 

[AnnS]

The network mode not APN settings @tomm2000 .

I have got to admit I am running out of ideas when your network mode is selected to 5G 4G @tomm2000 

Try refreshing your SIM on the network by completing a manual roam by following this information

How do I perform a manual roam? 

Also try going into offline flight mode and back on the network and in an alternative location.

Absolutely no reason for the phone not connecting to the 4 and 5G network.

[tomm2000]

Also toggled between the different network mode settings but no luck. 

[BandOfBrothers]

Hi @tomm2000 

My partner uses the Samsung s21 fe but on o2 and gets 4G fine.

In the phone's settings > Connections > Mobile Networks > Network Mode it has 4G/3G/2G (auto connect) available. 

Can you try another networks sim card in the phone to see what happens. 

If I can be of any further help then please don't hesitate. Take care.  😎 

Can you run the diagnostic tool found in your Samsung Members App to see if that highlights anything. 

[tomm2000]

Tried the Samsung members app. Reported the sim card was normal. 

Getting to the point where I will have to return the s21fe as faulty (perhaps it isnt) which would be a shame 

[tomm2000]

Tried the aeroplane money on and off. Tried switching to another network and back.

Using the sim card in my old s10 under Network Mode, I can see LTE/3g/2g(auto connect)

On the s21fe I don't even have the Network Mode section. 

[AnnS]

The phone won't be faulty @tomm2000 , I would recommend going into a Vodafone  Store with the device, they staff will be able to check 4 and 5G is enabled on the network mode.

Vodafone don't have the FE listed on device guides but the 5G will be exactly the same, take a look at device mode here https://deviceguides.vodafone.co.uk/samsung/galaxy-s21-5g-android-11-0/connectivity/select-network-m...

[tomm2000]

I appreciate any advice but I don't even have the Network Mode section  on the fe