I installed my Deco X50-5G recently, using it in Bridge Mode and connected by ethernet backhaul 3 XE75, which form their own mesh wlan. The Deco X50-5G Wlan is only used to access this device. 

I received a new firmware availlable info and tried to install it, but it did not work. Is it a question of the Bridge Mode?

Unfortunately in the moment I do not have access to the system, it is in our holiday appartment, so I can not repeat the procedure to get the exact messages, that and why it did not work....