How many WX5600-T0 can I connect to EX5601-T1

Hello

I have a EX5601-T1 modem/router from my internet provider. I also ordered 3 WX5600-T0 wifi extenders. I use them at home as follows:

EX5601: groundfloor, cabinet near front door

WX5600 (#1), wireless: groundfloor, living room in the beack to cover garden and garage.

WX5600 (#2), wireless: 1st floor, hallway to cover rooms first floor

WX5600 (#3), wired to EX5601: 2nd floor, to cover my small home office room.

So far the installation went fine and I have good wifi coverage where I need it.

But I'm having problems with a internet connection that keeps dropping out. Sometimes all LEDs on all devices will stay green and Wifi will show "connected without internet". And the connection wil come back by itself. Sometimes the connection will stay out and the earth-signal on the EX5601 will turn red. And only a power-reset will restore the signal.

My provider says it is because I had two 5-port gigabit switches connected that causes problems. but they also say I can not connect more then 2 WX devices in my Mesh.

I read in your WX5600 manual you can use max 3 WX devices in a daisy-train for a Mesh network? And I remember one needs to be hardwired.

So I have two questions:

1. Is my current setup of Zyxel devices a correct working setup?
2. can connecting a simple 5 port gigabit switch to on of the LAN ports on the EX5601 cause problems, that may cause internet connection drop out?