I've been having this same issue in every game I try to play as well. Preseason or regular season doesn't matter. Simmed games don't have any issues, and it's only my human controlled team. I've attached screenshots of the box score after the game.
Here's a
YouTube video of me going from launch screen and playing the 1st period all the way through. At 0:14, you can see my starting defensemen are Hanifin/Klingberg. At 0:25, the game switches in Brodin (weird at 0:03 into the game). At 1:59, Jamie Benn goes from 1 shift to 7, and the team starts bugging out then. It's sporadic where it'll be normal for a minute or two, then go crazy again.
The OOTP Support FTP server isn't letting me connect, so here's a Dropbox link to the
saved game.
Computer specs in case it helps:
OS: Windows 10
CPU: i7 7700k @ 4.6 GHz
RAM: 32 GB
GPU: GTX 1070