CheckPoint no longer internet access after changing default route on Gaia.

[BlueGrass]

Dear All,

A simple case of standalone deployment with a fresh Trial license imported CP.

I have two internet-accessible WANs. 

Let says Gateway A is 1.2.3.4/24 and Gateway B is 192.168.1.254/24.

At the first time wizard, I do configure the default gateway using 1.2.3.4/24.

MGT port is the management interface with 192.168.1.1/24 as default.

And is able to ping www.google.com from CLI this moment.

Then I change the default route from 1.2.3.4 to 192.168.1.254.

The CP is no longer internet-accessible now.

I then use a PC to simulate the CP MGT IP  - 192.168.1.1/24 and able to access Google via 192.168.1.254.

I type "show route" on CP, the route looks good with the right interface chosen.

On the SmartConsole side, only Any <-> Allow Policy is configured at that moment.

Have someone try a similar case before?

[PhoneBoy]

Precisely how are you determining Internet accessibility?
Have you used, say, tcpdump to verify traffic is going out the correct interface with the correct IP address?
Are you seeing anything in the logs?
Also it's not clear if each ISP link is connected to the same interface or different ones.