WFI ISSUES WITH S25ULTRA 5GHZ BAND REJECTION

[Valley05912]

I just received my Ultra25, and I'm experiencing a very concerning issue. When I first set it up, it didn’t detect any of my home’s 5GHz networks—despite having two separate 5GHz networks on different routers. I successfully transferred all my data from my Fold 4, but the problem persisted. I spent the entire night exploring options and, through the hidden Intelligent WiFi Labs menu, I managed to configure it to display the 5GHz networks.

What frustrates me is that, on dual-band networks (both 2.4GHz and 5GHz), the phone recognizes the available 5GHz networks but opts to connect to the 2.4GHz band instead. It only connects to 5GHz when the network is exclusively 5GHz. Clearly, this is a software issue—updating the phone to the latest version has not resolved the problem. My model is the SM-S93B/DS with 512GB.

Please provide an urgent solution  #SM-S93B/DS #ULTRA25 512GB 

[GusB]

https://eu.community.samsung.com/t5/galaxy-s25-series/s25-ultra-is-not-showing-5g-wifi-networks/td-p...

Someone else posted a similar experience - it's not something I have an issue with - maybe you can find a similarity between the 2 of you @FazlayRabby

[Valley05912]

Hi there! I've reviewed that post and offered a partial solution, although it's not definitive yet. I'm still actively searching for a complete fix—it’s incredibly frustrating to encounter this issue on a brand new flagship phone.

[Reylob]

5GHz has a shorter range than 2.4 GHz and 6GHz has a shorter range than 5GHz. If you are moving around home, the fastest networks might become weaker and the phone automatically selecting the 2.4GHz. The phone always default to the last connected network.

Separation of the network by frequency is the only way to ensure that you phone connects to the right one.

[Valley05912]

Hello! After considering your feedback, I tested my connection near my modem, but the issue persists. It's worth noting that my Fold 4 doesn't experience this problem. Additionally, my Ultra 5 still doesn't detect the 5GHz network in my home, while the Fold 4 detects and connects to it automatically before switching to the 2.4GHz network if needed because of signal strenght. The Ultra 5, however, doesn't detect the 5GHz network at all.

[Reylob]

Hi @Valley05912 

That is confusing, on the original post you said: “It only connects to 5GHz when the network is exclusively 5GHz.” and in this post: “my Ultra 5 still doesn't detect the 5GHz network in my home” one statement contradicts the other. What do you mean by doesn’t detect? When you open the WiFi menu to join a network the 5GHz networks do not show in the list

I think we are using the same word with different meanings, so let’s try to remove ambiguity. Please correct me if I am wrong. I assuming Ultra 5 is the S25 Ultra (S25U).

I will ask you a few questions to see if we can get to the bottom of this.

Does your S25U connects to exclusively-5GHz networks?

Does your S25U cannot detect any 5GHz network at home?

Does your S25U connect to any 5GHz network anywhere else?

What routers do you have?

Have you done any customisation on your home network? e.g. you modified the way IPs are given to the devices, IP ranges.

It is common to have a single SSID (network name) for all frequencies, e.g my_wifi and it serves to clients for 2.4 and 5 GHz, some internet providers do it by default. If you have that setup then the router and the phone will negotiate, and it depends on both devices which frequency is used. To ensure that you control the frequency you need to separate them. e.g. my_wifi_2.4 and my_wifi_5 for 2.4 and 5 GHz respectively.

Are you comfortable with networking? Can you modify your routers’ settings?

You could check the authentication method on the router. You could change to see that makes a different. Alternatively, you could leave the network open for a very brief period to check, but I do not recommend leaving it open. Please note that if you change router’s settings clients might disconnect until the settings are back to what they were.

[Valley05912]

Hello, I understand the confusion, so I'll simplify everything: my S25U (Samsung Galaxy S25 Ultra) wasn't detecting or displaying any 5GHz networks in the list when I tried to configure it for the first time. After adjusting settings in the hidden Intelligent WiFi menu, I managed to get the 5GHz networks to appear in my WiFi list.

I have two routers at home: one that exclusively operates on 5GHz and another that functions in dual-band mode, which selects the band with the best signal while always prioritizing 5GHz. The phone connects and works perfectly with the router that's exclusively 5GHz. However, on the dual-band network, it only connects to 2.4GHz. This doesn't happen with my other devices, including my Galaxy Z Fold 4, which always use the 5GHz network on the dual-band router.

The same issue occurs at my office, which uses a dual-band router where my S25U chooses the 2.4GHz band, while my Fold connects to 5GHz. I'm not sure if this requires additional configuration or if it's a bug in the ROM. I dont want to mess my router settings since its properly working on all my other devices. 

[Reylob]

It seems that the phone works then.

If you want to troubleshoot the issue then you might need to check the setting of the routers. It might well be the way the router prioritise the connections. However, in any multiband network there is no no way of fixing the frequency a client connects to. Generally this is done by the server, which in this case the routers are.

[Jeroen1979]

I got the same problem. I also have a S25U 1tb. I can see the 5ghz ssid's but I cant connect to them. If I put them in dual mode with also 2.4ghz active it will connect but I can see in my router setting my S25U only connects to the 2.4 ghz band. I also have the new Tab S10 plus and a S22 Ultra, no problems with both of them.

[Jeroen1979]

I think I already found the reason. If I put my phone mac adress on random it will not allow me to connect. If I set my phone Mac adres static to his original Mac adres it alows me to connect. I dont have any Mac filters on my network. I also have no problems for my other devices. Looks like a bug in my phone firmware.