My Data Stopped working

[terryotots]

I just tried this and it didn't work.  My data was working fine and yesterday stopped working.  My account is up to date and active and has data available but it doesn't work.

[terryotots]

It seems that when I set preferences to 4G I can not access mobile data but can receive MMS messages.  When I switch to 3G I can access mobile data but not MMS.  It is a hassle that I can't find a work around for except for manually switching in between the two for the two separate purposes. 

I can live with this but don't understand why this happened suddenly.  Last month both worked all the time.

[hTideGnow]

HI @terryotots 

i think your phone only has band 2, 5, 7 on 4G LTE, which are not enough, you need more bands.  Having only some but not all compatible bands means it might not work on 4G all the time, won't be stable

[terryotots]

I don't understand the bands but the phone is supposed to be 4G VoLTE.  There are options in the settings for 4G so I think it is capable?

[hTideGnow]

HI @terryotots 

yes, your phone does not have the proper 4G/LTE bands.  It is good it works on 3G now. But there is a chance the 3G network might comes to an end in 2 years, no firm date yet.  But your phone won't work once 3G network is shutdown

[terryotots]

It has 4G bands.  I don't know how the preferences got changed or why it suddenly stopped working.  I did go to the US (I didn't buy roaming or data).  Could the auto settings on my phone have changed when I was there?  Not sure.

I appreciate your help.

[terryotots]

I have Qin/Xaiomi F21pro.

[hTideGnow]

HI @terryotots 

first , it is great your data is working again

But your 3G plan should still allows you to use the 4G network unless your phone has only the compatible 3G bands and not the 4G bands.  What phone you have?

[terryotots]

Thanks for the reply!

I did that too but it didn't work.  When I looked closer at my plan I noticed it was 3G speed.   My preferrred network settings were somehow changed to 4G.  I set them to 3G and now my data works.

[hTideGnow]

HI @terryotots 

did you try to reboot your phone?  and make sure you phone settings do not have the data limiter enabled