Add 2nd WAN / beginner

Hello everyone, I am having a problem when trying to add DHCP client for the ether2

Couldn’t add New DHCP Client - can not run on slave interface (6)

OK, I’ve read I must go to BRIDGE / Ports and remove from there ether2

When I do that, interface hangs for a moment, (I guess the routerboard is rebooting), and then I lose all connectivity to internet, can’t get IP address again from routerboard, etc, I have to factory reset the router, and run the quick set again,

ether1 = ISP1
ether2 = ISP2
ether3= empty
ether4=wireless router
ether5=cable goes to my LAN switch

Is there something I doing wrong?

Thank you for the help and welcoming me

Dont use quickset!!! and use the safe button in winbox.