This is still occurring. If I save the part in "Wireframe with Visible Edges", close Inventor, then re-open the part, it comes up as "Shaded with Edges". So, apparently, the visual style does not save. If I now switch to "Wireframe with Visible Edges", the lines are back. This happens on every part. I have attached one to see if it is my system configuration.
Dell Precision 5820 Desktop
Windows 10 Pro for Workstations Version 21H2 Build 19044, 1645 64-bit
Intel Xeon W-2225 CPU @ 4.10G GHz, 4 cores
16GB 2x8GB DDR4 2666MHz RDIMM ECC Memory
2.5" 256GB SATA Class 20 Solid State Drive
NVIDIA Quadro P2200 5 GB GDDR5X - Hardware Acceleration is On
Inventor Pro 64-bit Build 271, Release 2023.2