I’m having a serious speed issue with my Deco X55 3-pack and I’m hoping to get some help.
My setup:
    •    3x Deco X55 nodes
    •    Main node connected via ethernet to fiber modem (500 Mbps subscription)
    •    2 satellite nodes on wireless backhaul
    •    Firmware: 1.8.0 Build 25102213 Rel. 43970 (latest)
    •    QoS and HomeCare are both disabled
The problem:
The main node is only getting 0–8 Mbps from the modem, despite the same ethernet cable delivering 440–500 Mbps when connected directly to a laptop. After a factory reset of all nodes, speeds recovered to 400–500 Mbps for about 15 minutes before dropping back down again.
I’ve already tried:
    •    Replacing/swapping the ethernet cable
    •    Full factory reset of all 3 nodes
    •    Disabling QoS and HomeCare
    •    Confirming firmware is up to date
Based on reports from other users on this forum, this appears to be a known firmware bug in v1.8.0 affecting wired WAN speeds on the main node. I’d like to request a firmware downgrade to a stable previous version, does anyone know where I can do that and how?

Thanks in advance.