@sshiers Not an uncommon problem.
See this post Primary mouse DRG immunocytochemistry troubleshooting - cell detachment - #5 by achamess
I followed the protocol in the linked paper. PDL, then laminin, no washes of the laminin. Just DRG directly applied after aspirating laminin. Make sure reagents fresh. I used 4% PFA for fixation. Be super gentle with your washes.