Hi, I am from the support team.
I have few questions for you :
1. Can you let me know the 3dsmax & corona version you are using?
2. Is your graphic driver & other drivers up to date?
3. Have you monitored your CPU temp for overheating?
4.Have you tried to do a clean uninstall & then re-install to see if that solves that problem?
5. Can you send me your scene for a close inspection? You can upload your scene using our private uploader :
https://corona-renderer.com/uploadOnce you have done uploading your scene, do let me know the file name.
Looking forward to hearing back from you.
Regards,
Avi