Develop Bugs

[Q] 3G problem after 7th July update, ZE550ML

Hi, i have a weird problem,it started the day after i updated my phone. I used to have full 3G signal and download speeds up to 9Mb/s but now I can't connect to 3G, and when i put my phone on only 3G mode it won't find any signal and if it finds i can't register on it. It only can connect to 2G netword and I'm stuck with edge connection. What do u think the problem is?

new phone, no signal

I just got a new Zuk Z2 today. I'm using Straight Talk w/AT&T and I get no signal what so ever. My old phone has 3-4 bars of HSPA signal on said network. Anyone know if there is a trick to getting this to work or is the new phone a bust?

Same issue with me too.....help asap

alot of people has this problem, including my self, nice phone but **** hw

I having lenevo z2(2132) , but no network signal on phone, I tried all CN ROMs 1.9 than 3.1 but nothing helped to get network no 2G , 3G, or LTE, I can see my imei no. Correctly , wi-fi works also. But no network at all. Restored XCNN. Files also from zuk forum.
Phone is rooted with TWRP now. If any...
Solution...
Thanks

Slow 4G Speeds, connectivity issues. Modem, Baseband

Basically the Redmi note 5 Pro and Ai are really slow for internet speeds, unstable I compared it to Samsung S7. This post talks about the same problem.
https://forum.xda-developers.com/redmi-note-5-pro/how-to/low-signal-poor-4g-speeds-t3777925
It was so slow i was going to sell this.
When using a custom roms, the LTE connection would turn off even tho it was turned on, you click it and it says turn off LTE connection even tho it's already stopped working, no LTE icon present. Then after turning it off and turning it back on it works again, till it randomly disconnects itself again. Restarting the phone while LTE was working would normally mean it had the same problem when phone started up, LTE icon missing internet not working you click on it and it says turn it off, it's on but not working.
MIUI didn't seem to disconnect those issues above still hopelessly slow speeds however.
I found someone else who suggested flashing a modem to fix it, however this didn't work for me as there's a massive list modems i tried and didn't fix it below. Had to use aeroplane mode after each modem flash and turn it off and wait a bit before turning on LTE to get a connection.
What did fix it was this post i came across from another person.
As far as I see it's issue with MIUI9. What is my conclusion so far is, with MIUI9, there is an issue with network switching like from 4g to 2g or 3g and the phone gets briefly disconnected from network . This is more often when you use data than voice.
I use two sim cards so I've currently got my data sim set to LTE only and my calling sim is just on WCDMA as soon as i did that my download speeds match my S7 just as fast which wasn't even close to been possible before i did this. So i'm convinced that the persons post is correct and it keeps disconnecting from 4G to try and connect to 3G and results in an unstable connection. That and i ran speedtests against all those modems listed and couldn't get these speeds.
It might be possible to set my calling sim to WCDMA/LTE and data to only LTE not tested so far, so its working but if i lose LTE connection it would normally drop to WCDMA so with LTE only that could be problematic. Doesn't seem to disconnect anymore and maintains the LTE during phone restarting.

This is a list of all the modem, baseband files i tried.
These where from China rom.
9.5.16.0
8.8.9
8.8.3
8.6.28
8.6.21
8.6.16
The rest were Global, Stable and Beta
10.0.1.0
9.6.4.0
9.6.3.0
9.5.17
9.5.14.0
9.5.13.0
9.5.6.0
9.2.7.0
8.9.20
8.9.13
8.9.6
8.8.30
8.8.23
8.8.16
8.8.2
8.7.26
8.7.12
8.7.5

I just got the Mi 8 Lite yesterday. The speeds showing for mobile data on the phone are really slow... and downloads from the Play Store take forever (a few seconds for each MB). Trying to download the Android 9.0 update was painfully slow. Eventually I resorted to putting the SIM back into my old device and using that as a hotspot to update my phone via "wi-fi".
I have now placed the SIM back into the Mi 8 Lite and the mobile speeds are still slow. I'm really confused, however, because when I use the Mi 8 Lite as a hotspot to share the data with my old device, the downloads on that phone are quick.
So it seems that the Mi 8 Lite is just struggling to make internal use of the data speed that it is actually receiving from my network... it still transfers the full speed to other devices via the hotspot.
Any suggestions?

General my findings about network reception

i had many issues about my network reception most of the time i had no reception and could not make calls and surf the web
now i found somthing and i want you to confirm plz
i have no case on my phone so...
when im holding my phone bare hands the network signal drop down and up down and up
now when i put my phone on the desk the signal looks more stable without many droping in signals
wtf......?
maybe i found the issue?
more.... : 1 more thing that i check was my carrier services via googleplay and it was from 15.11.21 last update
my son got the same phone and his last update was 07.12.21 wtf?
so i download his vertion via apk mirror so.... will that maybe work now?
maybe now i will have less dropping in signals?
ill update later

Question no internet connection when switching from 3G to 4G

hello everyone, im having an issue on my poco f3 it happens on both miui official, eu v13 & 14
like title says, whenever switching from 3g to 4g there is no internet connection and i have to turn airplane mode on and off for it to work again...
you can trigger this issue by going to settings and manually changing to 3g and then back to 4g, but it can also happen automatically if the signal is low...
does anyone else experience this issue? is there any fix for this?

Shala1122 said:
hello everyone, im having an issue on my poco f3 it happens on both miui official, eu v13 & 14
like title says, whenever switching from 3g to 4g there is no internet connection and i have to turn airplane mode on and off for it to work again...
you can trigger this issue by going to settings and manually changing to 3g and then back to 4g, but it can also happen automatically if the signal is low...
does anyone else experience this issue? is there any fix for this?
Click to expand...
Click to collapse
3 possible reasons:
1) When youre using 3g, your phone is connected to the best signal 3g tower nearby, switching to 4g makes your phone use the same tower (could be a low signal 4g). When you turn airplane mode on and off, the phone connects to the best signal 4g tower nearby.
2) Faulty SIM card
3) Phone faulty hardware

3zozHashim said:
3 possible reasons:
1) When youre using 3g, your phone is connected to the best signal 3g tower nearby, switching to 4g makes your phone use the same tower (could be a low signal 4g). When you turn airplane mode on and off, the phone connects to the best signal 4g tower nearby.
2) Faulty SIM card
3) Phone faulty hardware
Click to expand...
Click to collapse
Thank you for your comment.
I dont think the SIM is faulty simply because when i insert it to my redmi note 9s, this issue does not exist.
does your poco dont behave like this?

country carrier always helps , what bands ? phone version global? that helps , https://www.kimovil.com/en/frequency-checker/US/xiaomi-poco-f3

jefffrom said:
country carrier always helps , what bands ? phone version global? that helps , https://www.kimovil.com/en/frequency-checker/US/xiaomi-poco-f3
Click to expand...
Click to collapse
Israel, pelephone carrier. phone global version from official poco store on aliexpress
happend on stable eea miui 13 & 14 also on global 14 and xiaomi eu 13 & 14