@juhovh 

I have directed the antennas towards the tower but I'm not sure in which direction the actual 5G antennas are pointing. I will try your suggestion and when I visit the property next time. 
 

As an update on my side, I have updated the Deco (iPhone app) this morning and my internet is back. Let's see how long this lasts but I'm wondering if there was something wrong with the app and the remote connection as well? 
 

This is such a puzzle.. 

  @Lmsp87 

I spoke too soon.. the connection got lost and back to the red light issue..