@Jules_F Somehow I managed to downgrade 2 out of 6 M5 decos with 1.9.1 installed. The other 4 are not downgrading. I used Tftpd as explained in https://www.tp-link.com/us/support/faq/2958/ I don't know why that is... Running only the 2 downgraded devices, made my network 100% again. Still trying the other 4. Later if I not succeed, will try to connect the rest to my network and see what happens. Shame on tplink for ruining the devices. 3 years running perfect 'till I decided to upgrade the firmware. I'll never do that again that's for sure.