Thank you both for the help!
Squid: Your solution was right on point. After I reseated all the connectors, booted, and did a parity check, parity check seems to be running at normal speeds!
johnnie.black: Great point about the cooling. You made me realize that one of the front fans wasn't getting enough power to automatically start with reboots. I fixed that and the temps are much better now.
Thanks again!