Squeezebox Radio keeps losing connection to LMS, mysqueezebox.com every night!

since about two weeks..

SB Radio keeps losing connection to LMS running on my Synology and mysqueezebox.com.
The device is shown connected to the router's WiFi, but the connection icon on the SB display is red.
All other SB devices (Chromecast, UPnP bridge, PiCore Player) remain connected.

Diagnostics after the connection fails:

Network Healh:
Ping LMS (192.168.xx.lms) not ok

Wireless Info:
Wireless Network: LGX2
Wireless Encryption: WPA2-PSK
Wireless Signal: 100%
IP Address: 192.168.xx.sbr
IP Subnet: 255.255.255.0
IP Gateway: 192.168.xx.1
DNS Server: 192.168.xx.1

Server Info:
mysqueezebox.com: -
Ping: -
TCP port 3483: -
TCP port 9000: -
Logitech Media Server: 192.168.xx.lms
Library Name: LMS
Ping: Can't Ping
TCP port 3483: Can't connect
TCP port 9002: Can't connect

Once I plugout/plugin the SBRadio, likely the connection is reset correctly.

What is the likely cause of this?
How can I further investigate, using debugs/logs?

Thanks a lot!!