I'm back as promised. Not sure what a sweep/integrity test is, but that's an interesting point about the connectors. I wonder if I should redo the jacks to see if it improves performance.
Where I'm at now - there does not seem to be an issue with the speed from Spectrum to my house. When a non-VPN computer is attached to the router directly, I pull as high as 350+. However, my router is only sending 100mbps to my switch (which is a gigabit switch). All of the other ports seem to be operating at full gigabit speed with each other (both lights light up), but I have an issue getting the full 300+ from the router to the switch. I wonder if I have a bad connection.
Pull the router's packaging out of the wastebasket and verify that it says " with Gigabit switch and network ports." If it doesn't say that, return it immediately and buy a better one that DOES say GigaBIt on the box. Make sure it also has several big ugly antennas to spray the WiFi signal throughout your work area.
Router definitely is a gigabit router (Netgear AC1900 C7000). Your first intuition was correct - one of the wires did not make it all the way to the end of the RJ45. Cut that off, put a new connector on, and am pulling 300+ at each ethernet drop point. Thanks!
buy one of the $10 cable checkers.. The sender indicates all 8 wires plus shield are connected and the receiver shows that they're in the proper order... =The one I have also does 2-4-6 pin telco modular connectors. Flatten out all 8 wires in the proper order then use a sharp side cutter to make them all the same length. I've not missed one yet, even with CCA wire (copper clad aluminum) needed black jacket and couldn't get solid copper in a hurry.
Yup, like I said, it only takes one wire slightly out of place to ruin your day. The $10 continuity tester is worth every penny. Just remember to change the battery. File it all under lessons learned the hard way ...