My phone is not showing all the wifi networks

[Kharl]

Hi!

since some months ago my phone shows to little wifi networks while all other phones around display up to 4 times the quantity of networks available. i have a second phone, an Motorola play e5 and in the same area, while my Motorola shows about 32 networks around, my S8 only shows 1, i hardly suspect that is only showing me 5g networks. i have seen that settings in others phone but i cant find it here, neither in developer area.

 

[svim]

Offhand I'm taking a guess that it sounds like something is going on with the WiFi antenna inside your S8. If the phone isn't able to detect local WiFi networks like it used to able to, there's a chance that a few months ago the connector between the antenna and the logic board just disconnected itself in some way. Could have happened purely incidentally, do you recall bumping your phone or just dropping it on a table around the time this issue started to become evident? But currently it sounds like your S8 can only detect a WiFi network that's in close enough proximity that the signal is strong enough that without the antenna other, lessor WiFi signals can be detected.
And to fix this, it's not a trivial task. The ifixit site has a number of repair guides for a S8 if you want to do this yourself. If you go here to Step 21, there are two antennas and one of them could be the source of the problem:
https://www.ifixit.com/Guide/Samsung+Galaxy+S8+Motherboard+Replacement/90316
If so, just re-seating both connectors might be the fix, but again this isn't a trivial project. Samsung loves to use a lot of glues and adhesives so tearing down your S8 requires the proper tools and equipment to disassemble and reassemble, plus there are the waterproofing seals that have to be replaced.

But the above is something that's more or less drastic. It could very well not be a hardware issue at all but just software. Try going into the Settings menu, and do a Network Settings Reset. This is similar to a Factory Reset but it's limited only to network related issues so it will wipe the settings for WiFi, cellular, and Bluetooth and return them back to their original defaults. Things like saved WiFi networks and saved Bluetooth pairings will be deleted so it's not to be done just on a whim.

 

[Kharl]

Hi!
Thank you for your answer.
i did replace the battery 8 month ago, i could have left an anthena cable loose or disconnected BUT, with the networks that appear, the farthest has the same strength in other phones.

 

[svim]

That's an important detail, if this phone was taken apart previously for a repair there could any number of issues that causing problems. Did you do this yourself or was it done by a service center? If elsewhere, take it back to have them look things over. There's a good chance something to do with their reassembly caused this issue, but you'll need to sit down and examine the timeline of events and don't be surprised if you have to prove there's a cause and effect issue, not just a coincidental failure of some part.
Did you try doing a Network Settings Reset though? At least minimize the chance of a software issue so you can focus on this being a hardware issue.