So after i upgraded the router from Vr900v towards VR2100v all is working as expected (even with ip reservation). All devices can reach out to each other nevertheless if they are joined to the same...

@Andrsouzaaa as already told i started with no fixed IP set but there was already the error active. So I tried to go one with the fixed IPs but there was no change.

@Solla-topee unfortunally it is even worth. Now the connection between RE and Router is also yellow. And within the router I can't find the RE anymore. Is it necessary that the IP range from the RE...

@Solla-topee Hi, thank you for the Support. Firmware can be found on Page 3 of the PDF at the bottom line. Should be the newest Firmware based on tplink Website. Build 20210907 Tel. 71667(6985) I...

@Andrsouzaaa i Had Reset the RE Multiple Times. I now ordered an vr2100v lets See If the Mesh functionality fixes my expectations

@Andrsouzaaa sorry for the misleading information i meant that i use Address Reservation for NAS To have a specific IP within the Network. So No Static IP only IP Reservation is used