Unable to access corporate network

I have been unable to authenticate into my corporate network/web portal for about 5 days.  I am having the same problem whether wired or wireless.  Contacted my ISP, and while they do not support my Router (I Own it), they suggested updating Primary and Secondary DNS to 8.8.8.8 and 8.8.4.4.  In order to do that, I have to enable Static IP on WAN Setup and add an IP Address.  I used 100.64.105.29, but TBH that was a wild guess.  But after applying I lost internet altogether.   I then selected Enable DNS Override on LAN Settings and applied but that didn’t seem to update nor did it fix the problem.  

So a couple questions:  Is there a different IP I should use on WAN Setup when shifting over to Static IP?  Or is there another way to update DNS without making all of the other changes described above?  
Or does the description sound like it may be on my corporate side.  

One last fact, this problem started after updating my MacBook to MacOS Tahoe 26.1...😡

Thanks!