Hi,

I have an issue: I changed ISP provider for an "upgraded" 100MB/s 5G FWA (I live in a sub-sub-suburban area where fiber is not available). 

Here is the current setup : 

ISP ROUTER (TOZED ZLT 51) --- ER605---- TL SG 108 gibabit switch ---- DECO X5_1. 

2 X50 are connecting via wifi blackhaul to the main DECO X50_1   

All cables are ETH cat 6 at least and the main cable from ISP to ER605 is cat 8. 

There is no other wifi network creating parasite. DECO has everything disabled (Smart DHCP, Smart beamforwarding ....) and is set in Access point. I tried in Main router it is the same issue.

The issue : 

The connection sometimes just drops and all connected WIFI devices show "limited internet access". When it works, the connection drops to an average of 45MB/s. 

When I connect directly to the ISP router with Ethernet (or tried reactivating wifi of the ISP router) : I can get speed tests of more than 90 MB/s.

The most annoying issue is connection dropping while WIFI is still ok. I can view chromecast devices and everything. 

This setup used to work when I had 2 WAN accesses linked to the ER605.

I suspect the ISP router causing the issue. I tried unpluggin the ER605 and plugging the DECO X50 diretly but the issue remained, especially of low speed.

What also bugged me, is at my parents' house who have the same ISP router with another internal wifi setup (mainly Amplifi) have the same issue. 

Whant can I check? is the Deco causing this drop/slow down ? I checked all LAN addresses and submask configuration, there shouldn't be any overlap between the ER605 and the ISP. 

I would really appreciate your help. thanks.