I have had a lengthy back and forward with support but to no avail.

My main deco updated to 1.5.1 no problem (new deco added to network). My three other decos (3 pack) have all stayed at firmware 1.2.8. I have tried setting up each deco as the main router and tried to update, but they won't. Tried directly connecting and setting up each one but no WEB interface (probably as older firmware doesn't have web interface). Reset everything multiple times. 

Now it is not affecting my internet but I had to make my newer deco the main deco, so if i take that deco out of the equation then i can ont update. I just find it odd and basic support was unable to help. I use to work in IT so I am no slouch and only contacted help after I had tried everything.

Anyone else come across this issue? The only thing I can think of is that a while back my devices were not moving between 2.4ghz and 5 ghz so the tp link technicians update my decos and maybe they have caused an issue with my firmware.

Anyway there is probably no solution as I have exhausted everything I can think of and I use to install these devices (100s). I just hate when devices don't funtion as they should.

Cheers