Hi,
The issue is solved in the latest DB of Corona which you can download from here: https://forum.corona-renderer.com/ Chaos Corona 10 for 3ds Max - Daily Builds Changelog
Please try the new DB and let me know if this solves your issue.
Note: The daily builds are the newest, experimental versions of Corona Renderer intended mainly for testing purposes and to showcase the recently added features. They contain the latest bug fixes but are not guaranteed to be stable, and in some cases can even damage scene files.
Check this link to know more about it: https://support.chaos.com/hc/en-us/articles/4528206493329-Corona-for-3ds-Max-Daily-Builds-