CBR750 has become a nightmare! Job at risk! Please help

2 things. 

1. you do have a ton of errors in the lines. The logs help confirm line issues but your errors alone are to many. 

Start with removing any amplifiers, signal attenuators, or splitters from the coax.
From there check the line for kinks, damage, moisture in the line.
Check the connectors for improperly made ends, foil touching the copper coax line, loose connections, bad/old/cheap connectors, or corroded connections. Replace them if you do.
If you can, simply connect the modem right where the coax comes into the home. This prevents wiring in the home from being the issue. And some ISP’s charge if the wiring issue is in the home. So this helps prevent this.

2. Whenever you're having issues and you're using multiple devices, simplify for testing. Connect your work pc directly to the orbi and make sure to get that stable first.