I too have a similar problem and see on other forums it is common.
I have just got the N8 ( New but was old stock from dealer) and all the Firmware (N8 - V1.03 and N8IEEE V1.07) are correct and up to date
The Yamaha Steinberg FW Driver is correct and the nExtensions loaded - V2.7.2
Cubase AI 4 is the latest version
N8 templates appear correctly when starting a new project - Firewire communication is fine - I can record on Cubase/channel, etc and everything works perfectly, except the remote control ( ie Cubase light does not come on)
I noted that N8 does not appear in the list of remote devices, so can’t add it and I think that is the problem.
I plan to Unistall Cubase and the nExtensions and reinstall and see if it works. If there are any suggestion it would be appreciated, thx
(The remote is not a big requirement for me but would be nice if it worked)