I found the problem. I was using layfrz to freeze the layers I didn't want, but when I picked one of the lotlines, it froze the p-lotline layer which turned off all the lot dimensions except for the ones along the outer boundary. Since all the other lot dimensions were not visible, I assumed that the p-lottxt layer was frozen.
I guess we just have to be careful with the layfrz command when dealing with xrefs because if you select a label, it will freeze the layer of the object the label is attached to instead of just the label layer.
Thanks for all the help and guiding me to find the problem.
Tom Berning
Woolpert, Inc.
Civil 3D 2020