I would try a factory reset on the Ignite modem, and then...

[rstra]

@brasha  I would try a factory reset on the Ignite modem, and then the router if that doesn’t fix the problem.

For an XB6:

Locate the Reset button on the back of your modem. It's located under the coaxial cable connection. Using a pointy object, press and hold the Reset button until the light on the modem changes back to green.

[mdk]

@brasha -- it's probable that a "factory reset" on the XB6/Ignite will result in the XB6 disabling "bridged" mode. 

Then, you'll have to:

1. re-enable "bridged" mode,
2. disconnect all Ethernet cables from the XB6,
3. power-off/power-on the XB6,

so that your computer does NOT obtain a "public" IP-address from Shaw's DHCP-server.

Then, reconnect the WAN port on your own router to any LAN port on the XB6.

After the restart of the XB6, you want the FIRST connected device, namely your own router, to be the device that sends a DHCP-request over the "bridge" to get a response from Shaw's DHCP-server.

[brasha]

Thanks so much for all the support! On Friday, I tried the steps you outlined and I believe things are working again. Unfortunately I had to make an out if town trip shortly after making the change so have not yet tested things as thoroughly as I want to.  I believe the major difference from what I had previously tried was disconnecting all 4 Ethernet cables attached to my ASUS router LAN ports. I will post again after I am home and done some further testing.