After multiple random disconnects with this error that persisted even if i manually entered my ISP's DNS i contacted support and they advised me to go for a replacement beacause the unit was faulty.

Raplaced the unit and the same thing happens with the new one!

This time i saw that you had a beta FW that may resolve the issue and contacted support to send me the link. 

The firmware they sent me is 0.4.0 0.9.1 v0070.0 Build 190128 Rel.5904Bn.

Dns error appears to be resolved but even if modem syncs at the same rate as before around 19000kbps,wifi speedtest appears to be only 3-4 Mbps which is unacceptable.

Reverted back to the stable firmware and speedtest came back around 15,5 Mbps immediately.

Is there another FW i could try or anything i could do to fix the issue?