Some customers do notice this after installation however it is simply the EdgeXOS or UBM appliance doing its job, which is to detect outages and/or high latency on your Internet connection.
If you wish to adjust the sensitivity for your connection you can do this via the Link Control parameters.
The other potential issue if you are running in proxy mode is that you are leaking ARP information, i.e. you have not installed the Edge as instructed directly between the router and your firewall/LAN network.
The EdgeXOS or UBM appliance MUST be directly connected to your WAN1 router, if the LAN network is able to see the router directly you will have issues as the router and the Edge will both ARP for the same addresses thus confusing the rest of the network.