After working without issue for some time, my Deco system now shuts down completely (red light, no internet) when the topmost Ethernet port is connected to my Ethernet switch. The switch is a Netgear

After the latest firmware update the deco continue to display Abnormal WAN Port speed and the download & upload speeds are capped at 94 Mbps. How can I at least downgrade to fix this issue? ISP suppor