Mobile data router issue

[iceycamoboy22]

So my internet is really bad and slow and I figured since the router/modem that I am using is really simple and doesn't seem to work well I could just take the sim card out of it and put it into a different one that actually has proper ports and antennae it would just work but when I swap the sim card out and restart the router so it recognizes it, it ends up saying no service and it sits like that forever and I'm not sure why because it has 5g service on the other router 

[SignatureSigner]

what provider are you using? what router are you trying to use?

[iceycamoboy22]

&

7 minutes ago, SignatureSigner said:

what provider are you using? what router are you trying to use?

The service provider is at&t with the talk net sim card and the router is an at&t router model MF279

[Donut417]

31 minutes ago, iceycamoboy22 said:

swap the sim card out and restart the router so it recognizes it, it ends up saying no service and it sits like that forever and I'm not sure why because it has 5g service on the other router 

You did make sure the new router does support the AT&T bands correct? 

[iceycamoboy22]

8 minutes ago, Donut417 said:

You did make sure the new router does support the AT&T bands correct? 

How do I check that it supports it?

[Donut417]

Just now, iceycamoboy22 said:

How do I check that it supports it?

Should be on the spec sheet of the router. AT&T's band should be listed somewhere on their website.