I had my entire shifter assembly replaced because it broke internally speed shifting into 3rd. When I picked up the car after the repair was complete, it would NOT go into 5th gear AT ALL. Turned around and took it right back to dealer. Srvc advisor sent it to technician right away and I got the car back in less than 15 min. They said all it needed was a simple adjustment. Shifts very smooth to this day.
I've popped off the boot to try and see where they made the adjustment but still unsure how they fixed the issue so quickly.

 

The problem is caused by the shifter not being adjusted far enough to the right. On the bottom of the right side of the blue part of the shifter, there is a channel that is supposed to line up with the black ridge that is located at the bottom right next to the torx bolt.

As a result the black plastic ridge scrapes off the softer blue plastic that makes up the right side of the channel.

To fix it, you need to adjust the shifter to the right. To do so, use a sharpie to mark the left/right adjustment clamp with the initial position. (See step 7 in this link[https://www.chevyhhr.net/forums/showthread.php?t=39396]. The left/right adjustment clamp is the white piece to the left side. The gray bracket to the right is the forward/backwards adjustment.) Once the initial position is marked, unclamp the left/right bracket and make an adjustment. Test the shifting. If still not in the right position, unclamp & adjust further. Continue to do so until shifting is smooth for all gears.

For more info on how to make the adjustments, just search for a TWM or BPS short shifter install manual/thread.

 

I am having a similiar issue. I have the covers off and same blue crumbs. Has anyone taken a photo post their modifications? I also had an issue with shifter being frozen in the winter 0 to -20 roughly it would not move. any thoughts on what grease to use?