Sorry I am not quite understanding you.
How about the internet access you set on the MR3220? 3G/4G only or WAN only?
Do you mean the 3G is the backup while the ADSL-WAN is the main connection?

Winston Berry wrote

Sorry I am not quite understanding you.
How about the internet access you set on the MR3220? 3G/4G only or WAN only?
Do you mean the 3G is the backup while the ADSL-WAN is the main connection?

The MR3220 is behind an adsl router exactly as described in Quick Installation Guide .

The main connection of the network behind the MR3220 is wan and i use the 3g as backup ( a low cost high availability solution)

Sometimes and although the terminals behind the first adsl are browsing the internet flawless the MR3220 has the hobbit to turn to

3g and does not failback to wan unless i switch it off/on ,,,

I'm having exactly same problem. My main connection is WAN and 4G is backup.
I set Wan with dynamic IP mode and then I try Wan PPPoE mode, and same problem.
When WAN fails, 4G is activated and connected, but the router cannot back to WAN.


There are any update or solution?

As I know, this problem has been fixed.
What's the model number? How about hardware version and firmware version of it?

Tony Seaford wrote

As I know, this problem has been fixed.
What's the model number? How about hardware version and firmware version of it?

Firmware Version: 3.17.1 Build 140929 Rel.40245n
Hardware Version: MR3220 v2 00000000

In Notes of TL-MR3220_V2_140929, it says " Fix the bug that the backup link won't revert to the main link when the main connection resumes to normal again;".
http://www.tp-link.com/en/download/TL-MR3220_V2.html#Firmware http://www.tplink.com/en/handlers/download.ashx?resourceid=11318

I will try to reset to factory default. But really, when PPPoE, the main connection is lost and 3G/LTE is activated, the router cannot back to main connection.