@Sokpan 

It must be because the phone still considers Wi-Fi signal from Main Hub good enough not to roam.

There is a way to convince smartphone roam faster:

On Samsung S22 Ultra under Settings/Network/Internet/[Deco SSID name]/Privacy make sure you have set "Use device MAC." Then, in Deco app, for that smartphone, under Connection Preference, configure to use 5GHz band only (under Preferred Wi-Fi Band).

Also, make sure in Deco app under More/Advanced you have Fast Roaming set to Enabled. 

Alexandre. wrote

  @Sokpan 

 

It must be because the phone still considers Wi-Fi signal from Main Hub good enough not to roam.

 

There is a way to convince smartphone roam faster:

 

On Samsung S22 Ultra under Settings/Network/Internet/[Deco SSID name]/Privacy make sure you have set "Use device MAC." Then, in Deco app, for that smartphone, under Connection Preference, configure to use 5GHz band only (under Preferred Wi-Fi Band).

 

Also, make sure in Deco app under More/Advanced you have Fast Roaming set to Enabled. 

@Alexandre. Thanks for the information.  Will make the changes and test for next few days to see if that works.

Alexandre. wrote

  @Sokpan 

 

It must be because the phone still considers Wi-Fi signal from Main Hub good enough not to roam.

 

There is a way to convince smartphone roam faster:

 

On Samsung S22 Ultra under Settings/Network/Internet/[Deco SSID name]/Privacy make sure you have set "Use device MAC." Then, in Deco app, for that smartphone, under Connection Preference, configure to use 5GHz band only (under Preferred Wi-Fi Band).

 

Also, make sure in Deco app under More/Advanced you have Fast Roaming set to Enabled. 

  @Alexandre. 

Looks like it won't change Deco.  It did switch to basement one when I was in my office after I made your suggested changes, had to stop wifi and restating it, but now back on main floor for past 1 hour it is connected still to basement Deco.

If I turn off wifi and back on, it switches to Main Deco on Main Floor. 

So it does switch Deco, but only if I have to restart WiFi to force it.

Any further suggestions?

  @Sokpan I have similar problem with my 3pack deco x20. At the beginning my phone was able to connect to any deco device, but after last firmware update I'm not able to connect to one of my deco devides. I tried to reset network, To recreate network, but nothing helps.

  @Sokpan 

That's all you can do to convince smartphone roam faster. I also run Deco Main Network on 5GHz only, so that I don't need to use connection preference per device to force it on 5GHz, but this will only work if you don't have 2.4GHz devices connected to Main Network.

When you restart WiFi on Samsung, you force smartphone rescan WiFi networks and choose where to connect. If it connects to the nearest Deco unit, it means scanning and roaming logic in smartphone is correct. It also means everything is fine with your Deco mesh, all nodes are up and running properly.

Every time smartphone decides to roam, it has to rescan the environment. That drains battery. For this reason, smartphones may not roam to the nearby WiFi node if their link to current node is still good. 

Check Samsung info page in Deco app, when you are on a different floor from Deco unit smartphone is connected to. If signal for smartphone is Fair or Strong, that could mean smartphone does not want to drain the battery by roaming. 

You can ask on Samsung forums if there is a hack to increase aggressiveness of WiFi roaming for that smartphone. You won't have this in regular Android settings, but maybe there is hidden parameter under developer screen that can be tweaked. 

  @Alexandre. 

I Have just tried to configure problematic x20 device as main device, and configuration failed(problem with initiall connection to wifi). 2 other devices can be configured as main device without and problem.  In my opinion problematic device can have broken wifi chip, i will return it to the store on warranty.

Here are some steps you can try to fix the automatic Wi-Fi connection issue on your Samsung Android phone:-

1. Router and Phone Restart:- A simple restart of both your phone and Wi-Fi router can often resolve temporary glitches. Turn them off completely, wait for 30 seconds, and then power them on again.
2. Check Router Range and Signal Strength:- Make sure your phone is within the range of your Wi-Fi router and has a strong signal. Weak signal strength can prevent automatic connection.
3. Wi-Fi Enable Auto Reconnect:-

• Open Settings on your Samsung phone.
• Tap on Connections or Wi-Fi (depending on your model).
• Tap on the Wi-Fi network you want to connect to automatically.
• Look for an option called Auto reconnect or Turn on Wi-Fi automatically and ensure it's enabled.

4. Wi-Fi Forget Network and Reconnect:-

• In the Wi-Fi settings menu (as mentioned above), tap and hold the desired Wi-Fi network.
• Select Forget to remove the saved network information.
• Now, tap on the network again and enter the password to connect freshly.

More details instruction below.

https://www.youtube.com/watch?v=JO8dtyFtlVg&ab_channel=TheGeekPage

  @Sam0121 Thanks for the suggestions.  Tried all these and still same results I am afraid. 

However, not sure if this is a solution, to keep rebooting routers, devices and Deco devices to fix issue with one device.  If the issue is with Deco, would like to see a real solution, if the issue is with Samsung mobile devices, then I will wait for them to provide a possible solution (already have reported it to them). 

At the moment I have switched back to my old wifi network, directly from the TP-Link router, which seems to fix the issue temporarily.  Just to make another point against Deco, have not been really pleased with their performance.  I had to setup a daily reboot schedule to address other issues like failing connection between Deco devices, slow speeds, and not able to connect to them.  Will test other mesh network, to see if that is more stable and reliable, and just sell my Deco devices.