ER605 mass client disconnection events
I am experiencing clients frequently being dropped from the LAN on ER605. Sometimes this is individual clients. Sometimes mass disconnection events when the entire LAN client group gets disconnected for around 10 minutes, as illustrated in this chart -
ISP is fixed wireless on ER605 WAN port with PPPoE connection and failover to Netgear 4G modem on WAN2 with dynamic IP connection.
Client disconnections are not associated with ISP failures / failover. This has been monitored by ISP for weeks and the ER605 is maintaining a stable upstream connection. The issue is on the ER605 / LAN.
ER605 connects to local network via three TP-Link switches in different parts of the building TL-SG1016PE, TL-SG108E and TL-SG1008P. The 8 port switches are currently on separate LAN ports on the ER605 but previously were connected through the 16 port switch with same issues experienced. I moved them to the ER605 LAN ports as I initially thought it might be an issue with the 16 port switch and wanted to test with it isolated. Disconnections persist across whole of network, not just the clients connected through the 16 port switch.
OC200 hardware controller (firmware 1.24.0) is connected via the 16 port switch.
There are two non-TP Wi-Fi access points connected, but issues are with Ethernet connections.
Network speeds via Ethernet are also very degraded. For example, the ISP connection is 120Mbps but speed test on a device connected to the TL-SG108E via Ethernet is only achieving download speeds of around 30Mbps with all other network switches connected, or around 75Mbps if I disconnect the TL-SG1016PE and TL-SG1008P from the ER605 before running the test. Streaming from YouTube or Netflix / other streaming services experiences frequent stalled stream and disconnections.
Aside from some IP reservations for specific clients and the failover to WAN2, the configuration of the network is as per the ER605 default with a single LAN and default VLAN.
Grateful for any suggested solutions.