S25 Ultra Wifi Conection is Slow

[pj25]

Hi everyone,

I just got my Galaxy S25 Ultra, and I’ve noticed that my Wi-Fi connection speed drops to 1 Mbps or even 0 Mbps at times. (Upload & Download Speed)

At first, I thought it might be an issue with my internet provider, but after running side-by-side speed tests with my old S22 Ultra, I found that the S22 gets normal speeds. I also tested my laptop, and it had the same stable speed as the S22 Ultra.

I checked the Wi-Fi settings on both the S22 and S25 Ultra to see if there were any differences, but everything looks the same. I also tried forgetting and reconnecting to the Wi-Fi on my S25 Ultra, which temporarily fixed the issue, but the speed eventually dropped again.

Has anyone else experienced this, or does anyone know how to fix it? Any help would be greatly appreciated!

Thanks in advance!

[GoanGeek]

Hi.

I would look into resetting WiFi and blue tooth settings under Reset or even Reset all settings and go from there.

[Gav4b]

it could be something Todo with your router you should try turning it off for 5 minutes then turn it back on and do the same with your phone I had the same issue on my s24 and that fixed it

[Noodlefu]

My S23 maxed out my WiFi (regularly near a gigabit). S25 Ultra can't even hold 250 megabit. Same router. Same connection. Something isn't right with the S25's WiFi... It's like it's stuck at 2.4Ghz...

[Vrushabh]

I have the same issue as well on my s25 ultra. The wifi connection keeps getting disrupted every now and then. YouTube, WhatsApp, X, clash Royale, Instagram any online application for that matter. But it works completely fine on my s20, no problem on my laptop either. So this is not a connection issue. I'm on wifi 5 network by the way (the number next to the wifi symbol). Can anyone please help? 

[Buddha Brand]

I am having the exact same issue. I can't seem to pinpoint when it happens but when it does I get anywhere from 0.04-1.4 1Mbps. It's incredibly frustrating and it doesn't go away resetting the network settings or rebooting the router. Sometimes it will go back to normal usage like right now where I speed tested and was getting 189Mbps, but out of nowhere I'll be back down to sub 1 speeds. I have no idea what's causing it in all other devices are working with no issues at all in the receiving expected speeds.

[CaptPat51]

Very strange - noticed that suddenly S25Ultra was running really slow loading web pages in chrome that should be fast, DL PDF's that were not progressing.... so I checked the routers and wifi - 3 gaming AX11000's on AiMesh all seemed OK, restarted the network, still .1MBPS (yes .1!) on the S25Ultra.   60 devices on the mesh network not having problems, including multiple gaming laptops.  Ookla on the wired LAN reports 850+Mbps Up/Down symmetric...  Tab 10+ does 348Down/249Up, not bad.  Flip6 does 152Down/96.4Up, Fine.  Fold6 does 153Down/99.2Up, Fine.   S25Ultra... wow.  throttles .1 Down/57.65Up.  Same Wifi, Same Verizon FIOS backhaul, Same DNS? , Same Server for ookla speed test...   So Disabled Wifi to test Mobile Data only...   T-Mobile connection and server for ookla test - Flip6 464Mbps Down/9.6Mbps Up - bit slow on the back channel, but great on the DL,  Fold6 378Mbps Down/2.93Mbps Up - hmm rather slow up... but different issue...  S25Ultra - .04DL !!! 6.09 Up.   Something is totally throttling data on both Wifi and Cellular on S25Ultra.  This is not cool.  Adaptive bitrate test on Flip6 says 2160p (4K), Fold6 2160p (4K), Video TEst Failed on S25Ultra.   Map can be displayed on both Flip6 and Fold6 quickly, took almost a minute to load on S25Ultra.  This not a WIFI issue - it is a throttled data connection above the Wifi and Mobile data merge point in the  network stack.  Time for some further analysis on the phone itself...  Anyone have tooling for this?

[CaptPat51]

this is not just WIFI it is Mobile Data also -  I have Flip6, Fold6, S25Ultra, and Tab10+...  Can confirm that S25Ultra has a local network stack issue.   Ookla speedtest throttled at  .08Mbps;)  upload 132 is ok but Flold6 does 292/232, and Flip6 does 445/248.    This occurs on ALL Wifi networks - including using the fold or flip autohotspots for the S25Ultra:) and also on T-mobile Data network 5g.  All settings are as identical as possible - something is throttling the network....   What local debug tooling can shed more light on this??  It's on the phone.  Reboot, etc doesn't help, it's network independent so local setting or 

[CaptPat51]

OK, I Disabled and then re-enabled Developer Mode - it is enabled on all my devices... That did not change the result.  Verified some other settings and then looked at Network Download Rate Limit in developer options - it was set to unlimited as expected so I SET it to 15!!!:)  and ookla immediately did 15Mbps DL:)  so I set it back to unlimited and it works now mostly;)  107Down/61.6Up, to one server, went to better server got 120DL, 83.5Up - mostly ok - this was Wifi, moved to TMobile 5Guc and video test says 2160p (4k), got 466Mbps DL/3.75UL - great DL speed, UL oh well...   So it looks like a bug in the network stack that reads the developer option as 0 and throttles at about...  setting and resetting it apparently kicks it appopriately and for now it's "unlimited" - although I think there's generally low upload speeds, and downloads are lumpy and vary within a factor of 2X - so maybe buffering or some sort of checking that's in the data path is getting in the way.  In any case, I'll take >100 over .01 any day;)    Samsung will have to fix in an update.

[CaptPat51]

it is not this.   problem is on the phone and network independent - mobile or wifi no matter - it's in the phone networking stack.