@Rattaplan OK found another post about this. There seems to be an error in the speedtest app it seems.

I have an gigabit connection. 1000 mbit down and 50 mbit up In router mode i get around 900 mbit with the internet speed test using in the deco app. But when i switch to accespoint mode same test...

@MDWatson The Lyric can only connect on the 2,4ghz wifi band. You could try to turn off the 5ghz band on the deco, Then connect the lyric, When succesfull turn back on the 5ghz again

@Rattaplan Problem still persists. Last night couple of times the connection drops. I noticed that now the whole Deco system is going offline. offline i mean that app says that the system is down....

@Rattaplan Ok another update after observing the specific connections. I removed the 1st floor deco from the ethernet connection link and moved it on room further. becaus i dont have a ethernet...

@TP-Link I am observating the situation for the moment. What seemed to help for now was removing te laptop from the dece app list and connecting it to the main deco again. Then when i took the laptop...