NEED HELP- can't access device if connected through wifi

My Cloud OS 3 Personal & Network Attached Storage My Cloud
1

SETUP:

My NEW ISP provided me with a new Modem/Wifi router ( it’s only 1 device)
but only 1 port is activated

so connected the network switch to the activated port

connected my Desktop to the switch
connected my My Cloud to the switch

Desktop to My Cloud shows no problems, i can open dashboard, transfer files etc etc.

problem:

when i use my laptop or phone connected to the Modem/wifi router through wifi, i can’t access my My Cloud.
BUT if i use the My Cloud Software on my laptop, it can detect the My Cloud BUT it will say " Failed to connect to the device"

if i type in the IP(i can see it with the My Cloud Software) on my web browser, nothing happens.

Note: if i enable the Cloud option on the Device, i can access the Files on my Wifi connected devices BUT it goes through the internet, not my local area network. meaning My Cloud has access to the internet but not my Wireless Local area network.

2

Make sure the WiFi access point isn’t a ‘guest’ network, connected only to the internet. You must be able to to access your local network by WiFi.