@yves_b Thank you so very much. Everything is is operating excellent. Thank you very much for your advice.

Thank you very much for your reply. I didn't know that I can plug the fibre directly into the Mesh. I thought I need the "old" touter to still do the DHCP. I take it from your reply that the "Main"...

Good day and thank you for your help. I installed a Deco M5 AC1300 (3-pack) two days ago. Main: Living room and is connected to the router into which our fiber plugs in. This is a TP-Link TL-WR845N....