Before closing try regenall and/or audit and choose not to fix errors. These usual fix most probs with civil3d objects.
If a post provides a fix for your issue, click on "Accept as Solution" to help other users find solutions to problems they might have that are similar to yours.
Andrew Puller
Maitland, NSW, Australia
Windows 10 Enterprise 64bit
Intel core i7 11800 @ 2.30 GHz with 32GB Ram
Civil 3d 2021