So I think I found the problem last night.
I think the auto setup wizard is not working correctly.
I went to the Status/Advanced setting of the router.
At the bottom checking under DSL for the DSL modulation Type I found that for my TalkTalk connection it is ADSL_G.dmt.bis
I then went to the Network/DSL Settings/Advanced setting
I found that it was originally set to ADSL2+. I set the DSL Modulation type to the G.dmt setting
When it was set to ADSL2+ I had already set it to ADSL2 to try and improve my SNR values. The SNR downstream (receiving data) was between 6.1 and 6.3 which is too low which I think was causing sync issues and therefore line drop. Now that I have set the modulation type my SNR downstream is above 12 and the line has not dropped. The SNR for both upstream and downstream should be above 10. Downstream is the most important.
Same problem on my Archer VR2800. I tried changing modulation type to G.dmt but then it wont connect, so i set it back to ADSL auto sync up.
My SNR numbers are 8.6 and 5.9db.
My old huwai router seems to work, but the new VR2800 was working fine for 2 months but now constantly connect/disconnect.
Talktalk and TPLINK helpdesks have no idea, so i have an engineer comign but could face a charge if they think its the router...
Any help appreciated
I have same problem with Archer VR900 , and I do some workaround and working fine up to now.
1- go to Advance
2- DSL Setting
3- Annex Type ===> Annex A
I hope it is work